Norman Neill Greenwood was a member of the group of distinguished post-Second World War inorganic chemists who created modern inorganic chemistry. He was particularly recognized for his contributions to the chemistry of the main group elements boron (especially the metallaboranes), aluminium and gallium and for his contribution to the application of Mössbauer spectroscopy to inorganic systems. He was also committed to the teaching of his subject and wrote several highly regarded books; most notably, he was co-author of a textbook on inorganic chemistry, Chemistry of the elements , widely regarded as among the very best of its kind. Norman spent most of his career at the Universities of Nottingham, Newcastle and Leeds. He was a highly active member of the International Union of Pure and Applied Chemistry and served on a number of committees, chairing several. He was particularly concerned with the establishment of 'correct atomic weights' and was involved with many of the issues associated with the discovery of the array of new elements and with the ensuing problems of isotopes.
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NORMAN NEILL GREENWOOD
19 January 1925 — 14 November 2012
Biogr. Mems Fell. R. Soc.
NORMAN NEILL GREENWOOD
19 January 1925 — 14 November 2012
Elected FRS 1987
By Brian F. G. Johnson* , Alan J. Welch, J. Derek Woollins,
Charles Johnson and Catherine E. Housecroft
Department of Chemistry, University of Cambridge, Lensfield Road,
Cambridge CB2 1EW, UK
Norman Neill Greenwood was a member of the group of distinguished post-Second World War
inorganic chemists who created modern inorganic chemistry. He was particularly recognized
for his contributions to the chemistry of the main group elements boron (especially the
metallaboranes), aluminium and gallium and for his contribution to the application of
Mössbauer spectroscopy to inorganic systems. He was also committed to the teaching of
his subject and wrote several highly regarded books; most notably, he was co-author of a
textbook on inorganic chemistry, Chemistry of the elements , widely regarded as among the
very best of its kind. Norman spent most of his career at the Universities of Nottingham,
Newcastle and Leeds. He was a highly active member of the International Union of Pure
and Applied Chemistry and served on a number of committees, chairing several. He was
particularly concerned with the establishment of 'correct atomic weights' and was involved
with many of the issues associated with the discovery of the array of new elements and with
the ensuing problems of isotopes.
Early life in Australia (1925–1948)
Norman was born on 19 January 1925 in St Kilda near Melbourne and was incredibly proud
to be the only member of his family to be born in Australia.
* Emails for contributors: brianjohnson828@btinternet.com; A.J.Welch@hw.ac.uk; jdw3@st-andrews.ac.uk;
cjohnson@utsi.edu; catherine.housecroft@unibas.ch
Note: Alan J. Welch and J. Derek Woollins wrote the section on boron chemistry, Charles Johnson wrote the section
on Mössbauer spectroscopy and Catherine E. Housecroft wrote the section on Chemistry of the elements.
2019 The Author(s)
http://dx.doi.org/10.1098/rsbm.2019.0015 3 Published by the Royal Society
4Biographical Memoirs
His early education was at Mont Albert Central School, followed by Canterbury State
School in Surrey Hills. His secondary education was at Auburn Central School (1937–1938)
and University High School (1939–1942). He excelled academically and had a very high
regard for his school education, especially at University High School where he felt he received
a truly first class education. At the sixth form level, pupils were divided into Pass VI and
Honours VI. Honours VI was intended for pupils who planned to go on to university and was
for two years. Norman had to choose Pass VI for financial reasons, but in 1942 was fortunately
able to obtain a Laboratory Cadetship at the University of Melbourne. This provided the
necessary financial support to enable him to attend evening courses after working as a lab
technician during the day. He remembered those days as being very long and tiring. This
period was during the Second World War and Norman became a member of a group studying
the shock effect of nitroglycerine as part of the war effort.
At Melbourne University, the old degree structure required that students took four subjects.
Norman chose to concentrate on chemistry, with two of his four chosen subjects being on
different aspects of this field. He did well and came second out of a class of 200. At the time
his lab supervisor was Abe Yoffe, who, recognizing Norman's talent, strongly advised him to
switch to the Honours course.
Abe and his colleagues treated Norman as a full member of their research group and
regarded him as a junior research assistant. The study of the explosive characteristics of
nitroglycerine involved specially prepared tablets containing nitroglycerine that were hit by a
hammer to cause an explosion. At one time Norman was required to collect fresh specimens
of nitroglycerine and he described with relish the car journey back to the lab with a flask in his
lap containing enough explosive (suitably desensitized in gutta-percha, of course) to destroy
Melbourne.
Melbourne University chemistry department set the very highest standards in both the
lectures and practical classes and almost all his teachers gained international reputations.
Norman was especially grateful to Erich Heymann, who taught him thermodynamics.
Although generally remembered as an inorganic chemist, it should be noted that Norman
was also a first class physical and theoretical chemist; he lectured at Harvard in 1965 on the
possible existence of inert gas compounds—well before their discovery—on the basis of a
simple but elegant thermodynamic cycle.
Being a part-time student, this effort was hard but rewarding. In his final year Norman was
attracted to inorganic chemistry by the excellent lectures of J. S. Anderson and to organic
chemistry by Norman Lahey. In both his second and final years Norman was top of the class
and was the class prize winner, but, more importantly, as a consequence, he was allowed to
choose his research supervisor—J. S. Anderson. It was at this stage that Norman began his
commitment to inorganic chemistry and met his life-long friend, Ray Martin.
J. S. Anderson was a world authority on non-stoichiometric compounds. Many inorganic
solids have less well-defined atomic compositions, particularly for those systems in which
a metal atom may exhibit more than one oxidation state, e.g. Cu(I) and Cu(II) or Fe(II) and
Fe(III). In his studies of these and other similar systems, Norman had to learn glass-blowing, a
skill that was to serve him well in his later work on boron hydrides. His research in Melbourne
went well and on the basis of this success Norman won an overseas scholarship, awarded by
the Royal Commission for the Exhibition of 1851, to undertake a PhD in Cambridge, England.
It was not all work. Somehow, Norman found time for tennis, skiing in the Australian
Alps, cycling and bush walking. He also participated as a flautist in a travelling minstrel show
Norman Neill Greenwood 5
that toured the local countryside. This he regarded as very influential in his understanding of
Australian rural life in the 1940s.
To England and Cambridge (1948)
Norman relished the opportunity to see his family's home country and often talked about the
strong sense of adventure in catching the ocean liner SS Orontes for the four and a half week
trip across the world. The trip (in August 1948) was not that straightforward and passing
through the Suez Canal during the Middle East conflict was quite an experience. Norman
was met by his English family and after an emotional reunion moved on to Cambridge where
he was to carry out research under the guidance of Professor Harry Emeléus. At that time
there was little interest in inorganic chemistry. Two men, Emeléus and Anderson, represented
inorganic chemistry at the time and Norman was greatly influenced by their book Modern
aspects of inorganic chemistry (1939). Norman and Emeléus immediately established a strong
rapport. After considerable discussion, it was agreed that Norman should study the properties
of the interhalogen compound iodine monochloride (ICl) and, in particular, its electrical
conductivity.
Work with iodine monochloride (ICl) stemmed from work going on at that time into
the study of non-aqueous solvents such as liquid sulphur dioxide (SO2 ), liquid ammonia
(NH3 ), liquid dinitrogen tetroxide (N2 O4 ), etc. At first ICl had to be prepared by passing
chlorine over iodine, which produced beautiful ruby red crystals of the required product
that, after purification, had a melting point of 270°C. It was an easy compound to handle
and its conductivity easily measured. Surprisingly, the conductivity increased (it was highly
conductive) until 450°C, when it diminished. This was difficult to understand, but significantly
no electrolysis was observed. The work proved to be a highly successful piece of research with
lots of results, the highest recorded melting point indicating excellent purity, but the results of
the conductivity were difficult to explain. On the basis of this success, Norman took a holiday
and went skiing.
To his horror, on his return he discovered that during his absence two Russian chemists,
who had carried out similar experiments, had published a series of rather impressive results
(Fialkov & Shor 1948 ). Under these circumstances, Norman felt he had no alternative other
than to move on. As a consequence, a slightly different approach was adopted. The compound
iodine trichloride (ICl3 , which dimerises to form I2 Cl6 ) was clearly related to ICl, but had
never been explored. Norman turned his attention to this similar, but chemically quite distinct,
compound and soon found that it was a far more difficult subject to study. Its melting point was
relatively high and could only be measured under pressure. Furthermore, it readily underwent
disproportionation to form ICl and chlorine. For Norman, this presented a new and difficult
challenge, although he said that if you had worked with nitroglycerine no further challenge
was truly difficult. He constructed a high pressure vessel to measure the conductivity of
this difficult compound. Even so, there were other substantial problems. Normally, platinum
electrodes are employed in the conductivity cells used, but it was soon apparent that molten
ICl3 reacts with platinum. Other metals were tried, but all presented their own particular
problems. Eventually tungsten was chosen, and the preparation of a suitable electrode was
accomplished. To carry out this work, a thick tungsten rod had to be turned down on a lathe to
5 mm thickness. This considerable effort brought success and Norman published his first joint
6Biographical Memoirs
paper with Emeléus (1 )*. Following this work Norman turned his attention to boron trifluoride
(BF3 ) and boron trichloride (BCl3 ) and thus began the first of his adventures with boron. The
work went exceptionally well and as a result Norman achieved his PhD in two years.
Cambridge experiences (1948–1951)
During his time at Cambridge, Norman was able to take advantage of listening to many
famous lecturers at the university. He found Emeléus a very impressive lecturer, relaxed and
informative. He also was very impressed with Sir John Lennard-Jones, the first professor
of theoretical chemistry in the world, and heard first-hand the brilliant work on molecular
orbital theory. Following his time with Emeléus, Norman decided that he needed a better
understanding of the new theoretical approaches in chemistry and chose to do post-doctoral
work with Sir John. Other notable lectures that Norman attended included Bertrand Russell,
Wolfgang Ernst Pauli (Norman admitted he did not understand a word), Sir William Lawrence
Bragg and Paul Dirac.
During this period at Cambridge, Norman travelled extensively. Together with friends,
he bought a 1935 Alvis open top tourer and motored through post-war Europe. One trip to
Norway with his future wife (Kirsten), Ray Martin and other friends, he visited and walked
across Lapland, in those days a very isolated place. He recalled with affection (!) the huge
mosquitoes.
Overall, Norman regarded his time at Cambridge as invaluable to his future career as an
inorganic chemist. He remained very impressed with Harry Emeléus, from whom he picked
up many useful, practical techniques, and with Sir John Lennard-Jones for providing a good
theoretical background.
Harwell (1951–1953)
After considering many possibilities, Norman chose to move to Harwell—then the British
centre for atomic research (Atomic Energy Research Establishment, AERE)—and work
under the guidance of Sir John Cockcroft. Although he gained some experience of handling
dangerous materials, he did not particularly value the time spent in the Harwell environment.
Nottingham (1953–1961)
Norman had decided on an academic career and successfully applied to the new university at
Nottingham for the post of lecturer. He often recounted that in 1948 there were 11 universities
in England and he witnessed and felt the excitement of a rapidly expanding tertiary education.
For him, Nottingham provided the stimulation and support he needed at this important stage
of his career. The head of inorganic chemistry at the time was Cliff Addison, whose interest
was in the behaviour and use of non-aqueous solvents such as dinitrogen tetraoxide (N2 O4 ).
Norman used to quote this work as an example of pure, or 'blue skies', research; investigation
for the search of knowledge without the urge for commercial success. Later, Addison's
* Numbers in this form refer to the bibliography at the end of the text.
Norman Neill Greenwood 7
work was to become invaluable in the development of rocket fuels for the American space
programme. Norman's work with H3 PO4 and D3 PO4 , with their different viscosities, also
proved to be useful in fuel cells since he was able to show that conductance took place by an
ion switch mechanism.
Norman also decided to work with other elements of the boron group: gallium, indium and
thallium. Initially with Ken Wade, his first PhD student, he investigated the chemistry and
physical properties of BCl3 and BBr3 and then later the synthesis of gallium hydrides. A clear
need for a better understanding of the formation and stability of these and other coordination
compounds was needed and, together with Peter Perkins and Ian Worrall, a calorimeter was
designed and built and the heats of formation of members of this class of compounds were
measured. In addition to proving himself to be an excellent research worker, Norman also
gained a reputation as an outstanding teacher and lecturer (figure 1 ).
In 1961, Norman was awarded a Doctor of Science (ScD) by Sydney Sussex College,
University of Cambridge (figure 2 ).
Joining the International Union of Pure
and Applied Chemistry (IUPAC)
During the 1960s, Norman was invited to join IUPAC. This was a time of rapid advances in the
subject, and IUPAC was essential to sustain and regulate the nomenclature used throughout the
chemical world and to establish the best values of key components such as atomic weights.
Norman was invited to sit on the team charged with the establishment of the 'best' atomic
weight for each element. This was no easy task. Following Dalton, each element had a fixed
atomic weight. Initially based on the value of 1 for hydrogen, and then 16 for oxygen, and
using different scales for different scientific groups, the value of 12 for carbon had eventually
been adopted. But the determination of atomic weight by different methods led to major
differences in their value; notably, values established from geochemistry following many years
of fractionation were often different from the values derived elsewhere. The major cause of the
problem was the existence of isotopes and the variation of their concentration brought about
by the differences in their rate of decay. For example, work by the French physicist, Francis
Perrin, on the 'natural nuclear reactor' in Gabon showed that, in contrast to the then known
values, there was a variation in the relative amount of 235 U present due to natural radiation.
The Commission on Atomic Weights, as the committee became known, was essential for the
provision of new definitions; for example, recognizing that a single atomic weight for a given
element was often not realistic, and that a range in which it may fall is of more significance.
Norman spent two decades with IUPAC and became president of the Inorganic Sector in 1970.
This provided him with the ideal opportunity to pursue his delight of travel—attending IUPAC
meetings all over the world.
Newcastle (1961–1971)
In 1961 Norman was invited to Newcastle as the first professor of inorganic chemistry. In
accepting the position, he was firm in his request that inorganic chemistry should be treated
on par with organic and physical chemistry. In his inaugural lecture, Norman chose as his title
8Biographical Memoirs
Figure 1. Norman lecturing—his lectures were fun and inspirational. (Online version in colour.)
Norman Neill Greenwood 9
Figure 2. Norman received his ScD from Sydney Sussex College, University of Cambridge, on
2 December 1961. He is shown here with his wife, Kirsten.
'Education through Chemistry', and was able to impart his strong views on the way chemistry
should be taught. It was his commitment to these views that led him to set up Chemistry
Teachers' Centres. The idea of the centres was to provide a place where, about once a month,
10 Biographical Memoirs
teachers from a ca 60-mile radius could attend a lecture combined with a social event. This
worked well. Similar activities were set up at about the same time by the Royal Institution,
and a travelling circus of university staff gave lectures at a variety of institutions. As a fellow
of the Royal Institution, Norman played a significant part in this venture.
In his inaugural lecture, Norman also concentrated on a similar theme, using the title
'Patterns of the Invisible' to support his arguments. In this lecture he discussed the shape
of atoms and molecules impossible to see with the naked eye. This enabled him to draw
the audience's attention to the rapid development of instrumentation and to point out that
the amount of chemical information in the literature was growing so fast that it created
challenges in the teaching of the subject. He was able to grasp the opportunity provided by
the development of new spectrometers to enhance his research activities and was among the
first to have access to the new far-infrared spectrometers as well as purchasing one of the first
nuclear magnetic resonance (NMR) (40 MHz) spectrometers.
At Newcastle, Norman's interest in fluorine chemistry was reignited. Like Cambridge,
Newcastle was one of the few places where fluorine was readily available. Work was extended
to iodine pentafluoride (IF5 ) and the compound was investigated in detail. At this time,
Norman began to consider the possibility of preparing the then unknown compounds of
the inert gases. He rationalized that the inert gas atom had lots of lone pairs of electrons
apparently available for donation and ionization potentials similar to other systems. It had been
established that for the series of compounds BX3 (X = F, Cl, Br), given the electronegativity
of F, BF3 was the poorest acceptor. This was thought to be because of the high reorganization
energy needed to give a tetrahedral geometry. In his experiments, liquid samples of each of
the three BX3 compounds were sealed in a tube with liquid Xe, but no reaction was observed.
In another series of experiments, Norman investigated the hydrides of boron, aluminium
and gallium, continuing work first started in Nottingham. In this work it was found that
one molecule of ammonia reacted with AlH3 to produce AlH3 · NH3 and, additionally, two
molecules would form the first five coordinate complexes of aluminium (AlH3 ·2NH3 ). The
gallium compound behaved similarly. One of Norman's most successful research periods came
when he ventured into the chemistry of the boron hydrides.
In the early 1970s, he attended a Gordon Research conference, where he heard about
Mössbauer spectroscopy. He immediately recognized that this technique could help solve
many of the problems he had encountered while investigating the chemistry of non-
stoichiometric compounds with J. S. Anderson. This was to become another dominating area
of Norman's research; he became a recognized expert in the technique and, together with Terry
Gibb, wrote a highly influential book on the subject (2 ). This book, which was intended for
those practising the method, became a bible for inorganic chemists. As he frequently said:
'If you want to understand an area of chemistry, write a book on it.' Equally important,
Norman had the good fortune to meet Professor Rudolf Mössbauer and together they formed
a substantial relationship leading to a widespread use of the technique.
Leeds (1971–1990)
Norman had enjoyed Newcastle and North East England enormously. He felt that Newcastle
was the place to be on both the academic and family levels, and he greatly appreciated the
support that the university gave. He had no intention of leaving there, until he received a
Norman Neill Greenwood 11
Figure 3. Norman was always very keen to encourage an interest in chemistry among school children.
(Online version in colour.)
letter from Leeds concerning their need for a new professor to replace Harry Irving, who
was retiring. The letter sought Norman's advice on possible replacements for the forthcoming
vacant chair. He responded, but to his surprise Leeds wrote back asking if he would consider
the position. For Norman this presented a real dilemma. Newcastle had provided an excellent
base for his wide range of interests, both within the academic circle of the university and also
his extensive involvement with the education of chemistry as an academic subject at all levels,
especially schools (figure 3 ). Nevertheless, after much discussion, Leeds persuaded Norman
to move, and the move proved to be highly successful. Within the department at Leeds there
were already several highly successful inorganic chemists, Bernard Shaw, Geoff Sykes and
Leslie Pettit, and with these by his side Norman was able to forge an outstanding department
recognized for its excellence throughout the chemical world.
A large number of Norman's research team went with him from Newcastle to Leeds.
Members of all the subgroups of his research effort (boranes, Mössbauer and solid-state) were
present and provided the much required continuity necessary for such a move. A new facet at
this stage was the more extensive use of NMR spectroscopy, especially with unusual nuclei
such as 27 Al, in addition to those more usually studied, for example 1 H, 13 C, 31 P and 11 B.
Norman recognized this rapid growth in the various spectroscopic techniques.
12 Biographical Memoirs
The lectures at Leeds were, similar to Newcastle, based on the then three sections
of chemistry: inorganic and structural, organic, and physical. The three heads of these
independent sections constituted the School of Chemistry. At the time of Norman's arrival,
the three sections were vehemently jealous of their independent authority. From the beginning,
Norman was chairman of the school; the headship rotated every three years, but the model did
not work well with such independence in teaching. At the time, the same problems existed in
other departments within the UK. After much hard work and perseverance, Norman managed
to raise the profile of inorganic chemistry and eventually the teaching was spread equally
among all three sections and worked well.
As head of department, Norman was keen to develop external relations. At first, he met
considerable opposition to the idea, but slowly he won over other heads in the university. The
first university open day was enormously successful and embraced not only chemistry but also
most other departments.
Meanwhile, Norman retained his activities with IUPAC and became involved not only
with ascertaining the correct atomic weight for each element but also identifying the person
or group responsible for discovering each new element. This was mainly directed to elements
up to atomic weight 101. However, new elements were being discovered or 'synthesized' and
the problem became far more complex. IUPAC came out with rules for the association of
the new element with its discoverer or discoverers. This involved a considerable amount of
investigation and diplomacy, but nevertheless seemed to work well.
Given the worldwide recognition of Mössbauer spectroscopy, and the contribution made
by the group at Leeds, it proved possible to set up a laboratory dedicated to the subject. This
laboratory was well furnished with state of the art spectrometers and other key facilities.
Staffing proved to be easy. Given the established reputation of the Leeds group, people
and visitors from across the world often chose to come with their own support. Work went
extremely well, and the group was able to study not only the common isotopes of iron and
tin but also other less easily studied isotopes of ruthenium, antimony and tellurium. Norman
always felt enormously proud of the number of people trained in that group. One aspect of
the research at this time was centred around the samples of moon rock provided by both the
National Aeronautics and Space Administration (NASA) and the Russian Space Programme.
This work gave Norman special pleasure and he was delighted to be invited to witness an
Apollo launch, something that he found totally overwhelming. Although the Mössbauer work
was clearly continuing to provide much valuable information, Norman felt he should spend
more time on his borane work, which also had rapidly taken off. As a consequence, he handed
over the Mössbauer project to Terry Gibb and, although he kept an interest at a distance, he
directed his efforts elsewhere.
Boron chemistry
Norman made major contributions to the chemistry of boron throughout his career, initially
as a PhD student working with Harry Emeléus in Cambridge on adducts of BF3 , and then
as a young, independent academic at Nottingham investigating aspects of the chemistries of
BCl3 and BI3 . His most significant work, however, concerned the boron hydrides (boranes),
studies of which began at Newcastle but blossomed following his subsequent move to Leeds.
Indeed, under Norman the University of Leeds developed into a major international centre for
Norman Neill Greenwood 13
boron hydride chemistry. There were three distinct strands to Norman's boron hydride work:
gas-phase thermolysis reactions; the development of boron hydrides as ligands to transition
metals; and conjuncto boranes and their derivatives.
Gas-phase thermolysis reactions
The lower boron hydrides are colourless, highly reactive flammable gases. They were
originally studied in the early part of the twentieth century by the German chemist Alfred
Stock, a scientific 'grandfather' of Norman in the sense that, following his PhD, Emeléus
worked for a period in Stock's laboratory in Karlsruhe. Stock managed to isolate and
characterize an initial six boron hydrides, but it was extremely challenging work given the
general lack of sophisticated equipment at that time and the fact that these compounds
were so unstable and tended to interconvert at relatively low temperatures. Moreover, the
structures of the boranes were then unknown, although it was appreciated that they could
not be structural analogues of saturated hydrocarbons because there were insufficient valence
electrons available. Thus, for example, B4 H10 could not adopt the same structure as butane
(C4 H10 ), since boron has one valence electron less than carbon. This led to the description
of the boron hydrides as 'electron-deficient' compounds, a misnomer that Norman and
co-workers were later to recognize and exploit with their studies of metallaboranes.
As a consequence of this 'electron-deficiency', the { BH} and { BH2 }fragments, of which
the neutral boranes are composed, cluster together, thus efficiently sharing the relatively few
valence electrons available and generally adopting structures that are recognizable fragments
of closed polyhedra. In many cases, H atoms bridge between boron atoms in the open faces
of these polyhedra. Stock's original six neutral boranes have now grown in number to > 50,
all of which are polyhedral fragments. At first sight, the array of these structures appears
overwhelming, but two key contributions in 1971 greatly helped to simplify and systematize
the area. First, Robert Williams realized that these structures fell into distinct families of closed
(closo) and open (nido, arachno, hypho, ... ) types. In this scheme, a nido species with (n− 1)
B vertices (or an arachno species with (n− 2) vertices, etc.) was recognized to be a structural
fragment of the closo parent with n B vertices. Second, Kenneth Wade (who had earlier been
Norman's first PhD student at Nottingham) perceptively recognized the underlying reason for
these structural relationships—that closo n vertex, nido (n− 1) vertex and arachno (n− 2)
vertex polyhedra share the same number of skeletal electron pairs—and thereby established a
simple set of rules (Wade's Rules) that underpin this area of chemistry.
It is a complex but beautiful and infinitely rewarding area in which to do research. At
Leeds, Norman took on the significant challenge of trying to understand the processes by
which the lower boron hydrides interconverted under thermolytic conditions. The objectives
were to establish detailed kinetic and mechanistic studies of reactions of the boranes in
the gas phase at modestly elevated temperatures. How, for example, does B2 H6 form B3 H7
when heated, and what are the mechanistic details when the B3 H7 so formed reacts with
another equivalent of B2 H6 to afford B4 H10 ? By what exact pathways does the thermolytic
decomposition of B4 H10 produce a mixture B2 H6 ,B
5H 11 ,B
6H 12,B
10H 14 and H 2? These are
complex and difficult questions and, in an attempt to provide answers, Norman turned to
mass spectrometry. Mass spectra of boranes are more complex than those of many species
because of the presence of two naturally occurring isotopes of boron, 10 B (19.9%) and 11 B
(80.1%), meaning that the spectra of molecules with multiple boron atoms appear as stepped
isotopic profiles. If there are several interconverting boranes present in the gaseous mixture,
14 Biographical Memoirs
the overall spectrum is exceedingly complex and to deconvolute it to gain information on the
relative amounts of each component is therefore challenging. However, two factors made this
possible. First, the masses of the two isotopes do not differ by exactly one unit (10 B, 10.013
amu; 11 B, 11.009 amu) meaning that 10 B+ 1 H and 11 B can be distinguished by high-resolution
mass spectrometry. Second, Norman recognized that the mathematics needed to deconvolute
these mass spectra were very similar to those used to deconvolute Mössbauer spectra, a
subject in which he was an internationally recognized expert. By coupling a thermostated
reaction vessel to a high-resolution mass spectrometer, Norman, working in collaboration
with Terry Gibb and Bob Greatrex, was therefore able to determine the exact masses (and
hence identities) and relative amounts of each component of complex mixtures of boranes in
gaseous mixtures as a function of time. Thus, they were among the first to use this approach
to establish detailed kinetic and mechanistic information on how these species interconverted.
These studies were subsequently expanded to also include gas-phase reactions of mixtures
of boranes and reactions between boranes and alkenes/alkynes, these producing carborane
compounds (clusters with B and C vertices) inaccessible by other means. An impressive
series of papers published between 1979 and 2000 documents this gas-phase work, and a
very readable summary of some of the key initial findings appears as part of Norman's Royal
Society of Chemistry Ludwig Mond lecture published in 1992 (17 ).
Boron hydrides as ligands (metallaboranes) and conjuncto boranes and derivatives
The idea of the boron hydrides as 'electron-deficient' is misleading. Certainly the { BH}
fragment, which is the major component of these species, is electron-deficient, but this
deficiency is obviated by the formation of polyhedral clusters, a fact that is supported by
the results of molecular orbital calculations on boranes and their derivatives, which generally
show that any unfilled orbitals are antibonding in nature. Boron hydrides can be reduced, but
this does not mean they are electron-deficient, since reduction results in a change in shape in
accord with Wade's Rules.
Norman was one of the first to appreciate this and to wonder if it meant that boranes and
their anions could actually be used as electron donors (i.e. ligands) to metals. It turns out that
indeed they can and, moreover, they do so in an impressive number of different ways. Early
studies had established that [BH4 ]− could coordinate to metals via 1, 2 and even 3 B-H-M
3-centre-2-electron bonds, and in the 1960s and early 1970s the American chemists Stephen
Lippard, Donald Gaines, Sheldon Shore and others subsequently showed that higher boranes
such as [B3 H8 ]− ,[B
5H8] − and [B 10 H 10 ] 2− could also bind metals through multiple B-H-M
bridges. Examples of species with direct M-B bonding involving boranes were also prepared
and characterized during this period.
An important breakthrough came with the discovery of compounds in which the borane
acted as a π -ligand to the metal fragment or, perhaps in a more useful description, the
metal fragment acted as a surrogate for a { BH} fragment in the borane. The first examples
of such metallaboranes were reported by Earl Muetterties and Russell Grimes in the early
1970s. In 1974 Norman, Russell Grimes and Alan Davison independently synthesized the
key compound [(CO)3 FeB4 H8 ]( figure 4), which they published jointly ( 3). As noted, this
compound can alternatively be regarded as a borane-ligand analogue of the well-known
organometallic species [Fe(CO)3 (η -C4 H4 )] or, alternatively, as a derivative of B5 H9 in which
the apical { BH} fragment has been replaced by an isolobal { Fe(CO)3 }fragment, although it
would not be for a further two years until Roald Hoffmann and co-workers developed the
Norman Neill Greenwood 15
Figure 4. The ferraborane, (CO)3 FeB4H8 , synthesized by Greenwood, Grimes and Davison
(reproduced courtesy of Alan J. Welch).
isolobal concept. In Leeds, the ferraborane was synthesized by the direct reaction between
Fe(CO)5 and B5 H9 in a hot–cold reactor and it became a landmark compound for the Leeds
boron group, being used as the illustration on the front cover of Greenwood and Earnshaw's
textbook, Chemistry of the elements (see figure 4 ).
At the same time as the [(CO)3 FeB4 H8 ] work, Gordon Stone (who had been a contemporary
of Norman's in Emeléus' group in Cambridge) and co-workers in Bristol published a
metallacarborane analogue prepared in an entirely different way. This was the beginning of
something of a halcyon period for boron cluster chemistry in the UK, which lasted through
the 1970s and into much of the 1980s, with Norman's group in Leeds working inter alia on
metallaboranes, Gordon Stone's group in Bristol and Malcolm Wallbridge's group in Warwick
researching metallacarboranes, and Wade's group in Durham and Michael Mingos' group in
Oxford providing vital theoretical underpinning of the experimental results.
The Leeds metallaborane work benefited from the confluence of a number of factors during
this period. First, unlike their borane parents, metallaboranes of the transition metals are
generally coloured, air-stable materials, making their isolation much more straightforward.
Reactions often gave rise to multiple products, sometimes each one in low to modest
yields, but these could easily be separated by thin-layer or column chromatography. When
questioned about publishing an unexpected product that had perhaps been isolated in a
yield of only a few per cent, Norman's reply was typically pragmatic: 'Characterising such
products shows what is thermodynamically possible, allowing deliberate syntheses to be
devised subsequently.' Second, the 1970s and 1980s saw significant developments in both
the hardware and software associated with NMR spectroscopy and single-crystal X-ray
diffraction. With NMR spectroscopy 11 B, 11 B{ 1H} ,1 H{ 11 B} 1D and 11 B/1 H and 11 B/11 B2D
experiments became routine and, for X-ray crystallography, automated diffractometers that
could rapidly collect low-temperature data became much more accessible. Both NMR
spectroscopy and single-crystal X-ray diffraction proved to be essential analytical techniques
for the Leeds metallaborane group. Finally, and perhaps most significantly, John Kennedy was
appointed to a permanent position at Leeds in 1975. Norman and John Kennedy, an expert in
16 Biographical Memoirs
Figure 5. Three isomers of the conjuncto borane B20 H26 characterized by Norman with John Kennedy
and co-workers; left, the 2,2isomer; centre, the 2,6isomer; right, the 1,2isomer (reproduced courtesy
of Alan J. Welch). (Online version in colour.)
synthesis and NMR spectroscopy, formed a powerful axis that oversaw the development of
metallaboranes and fused and conjuncto boranes and their metal derivatives, resulting in an
excess of 100 publications between 1978 and 2005. Space restrictions limit discussion of these
studies to one illustrative example of each of the areas.
The chemistry of isomeric icosaboranes, B20 H26
In one of their earliest collaborations, Norman and John Kennedy produced an impressive
series of papers concerned with isomers of the conjuncto borane B20 H26 , which consists of
two nido B10 units (as in B10 H14 ) linked by a direct B − B bond. As such there are, in principle,
11 geometric isomers, of which four should exist as enantiomeric pairs. Having first identified
B20 H26 as an impurity in technical grade B10 H14 by high-resolution mass spectrometry ( 4 ),
Norman and John Kennedy devised deliberate synthetic routes to B20 H26 and managed to
isolate up to eight of the isomers by chromatography (7 ). In back-to-back communications,
detailed NMR investigation subsequently proved that one of these was the 6,6 isomer (5 ),
while crystallographic study of another revealed it to be the 2,2 isomer (6 ). A subsequent
full paper included confirmation of the identity of a further isomer to be 2,6 (8 ). An unusual
synthetic route, high-energy electron radiolysis of B10 H14 , afforded three further isomers, 1,2 ,
2,5 and 5,5 (or 5,7 )( 9), the first of which was subsequently confirmed crystallographically
(12 ). Figure 5 shows the 2,2 ,2,6
and 1,2forms.
This was exceptionally challenging work involving innovative syntheses, careful
chromatographic separation and expert characterization. It not only established new
boundaries in boron hydride chemistry, since B20 H26 was then the largest neutral borane
known, but it also afforded sufficient amounts of material for subsequent derivatization, for
example metalation studies (10 ).
Metallaboranes
The studies of Norman, John Kennedy and their co-workers over a 25-year period did more
to open up metallaborane chemistry than anything previously or since. An exceptionally wide
range of metals from across the p and d blocks of the periodic table was incorporated into
borane clusters and the products fully characterized, both spectroscopically and structurally.
These studies allowed significant advances to be made inter alia in macropolyhedral
chemistry (13 ) and the fluxional processes in clusters (16 ). Occasionally, structures would
be elucidated that did not fit into the simple framework of Wade's Rules (14 ), and thus
Norman Neill Greenwood 17
Figure 6. The compound Ru3 {η 6 -B10H8(OEt)2 }(η 6-C6Me6)(μ-H)4 (reproduced courtesy of Alan J.
Welch). (Online version in colour.)
stimulated consideration of the refinement of bonding models. Aspects of Norman's work
on metallaboranes have been reviewed by him (17 ,18,21 ).
Interesting as individual metallaboranes undoubtedly were, Norman was always aware of
the potential for the area not to be thought of as an esoteric outpost of chemistry, but rather one
that was intimately connected with other parts of the subject; an idea he would emphasize in
his research lectures, particularly to audiences of younger scientists, whom he would always
encourage to think about chemistry laterally. This links to Roald Hoffmann's isolobal concept
whereby a fragment of a molecule could conceptually be replaced by a quite different but
orbitally equivalent fragment with no change in structure. In this way, the clearly related
areas of boron hydrides, carboranes, metallaboranes and metallacarboranes link to the vast
topic that is organometallic chemistry and thence to metal cluster chemistry. A particular
example from his own work that he often used to illustrate this principle is the ruthenaborane
shown in figure 6 . Here, a closo 11-vertex RuB10 cluster is part of an Ru3 triangle that also
incorporates two { Ru(η -C6 Me6 )} fragments and is edge-bridged by H atoms ( 15). Within a
single compound are metallaborane, organometallic and metal cluster components.
IMEBORON, IntraBoron and EuroBoron
Although Alfred Stock's seminal work on the boron hydrides was performed in the second
and third decades of the twentieth century, the subject did not begin to really blossom in
the open literature until the 1960s. By that time, a significant number of research groups
undertaking research into boron chemistry had developed, notably in the USA, Europe
(particularly Czechoslovakia) and the Soviet Union, but there was no formal way for these
groups to meet, discuss their common interests and potentially establish collaborations. Driven
largely by the prominent Czech chemists Stanislav Heˇ
rmánek and Jaromír Plešek, the first
international conference on boron chemistry was organized in Czechoslovakia in 1971 and
given the name IMEBORON (international meeting on boron chemistry). An informative
account of the origins of the IMEBORON series and a summary of the first nine conferences
18 Biographical Memoirs
Figure 7. Members of the IMEBORON International Committee at IMEBORON2, Leeds, 1974. Left
to right: V. I. Bregadze (Soviet Union), N. N. Greenwood (UK), S. Heˇ
rmánek (Czechoslovakia), M. F.
Hawthorne (USA), B. S. Thomas (UK, secretary), M. G. H. Wallbridge (UK). (Photograph courtesy of
V. I. Bregadze.)
appeared in 1997 (19 ). Norman was invited to represent IUPAC; at that time he was not only
an eminent boron chemist, but also very active in the Inorganic Chemistry Division of IUPAC.
The conference was an outstanding success, and the decision was taken to establish a triennial
series, with IMEBORON2 held in Leeds in 1974 under Norman's chairmanship (figure 7 ).
The IMEBORON series continues to this day with 16 meetings held so far, in 10 different
countries.
Norman was also a very strong supporter of IntraBoron, a series of semi-annual meetings of
UK-based boron chemists established in the late 1970s. IntraBoron ran successfully for almost
20 years before being assimilated into a new series of triennial conferences, EuroBoron, which
continues today. At the first EuroBoron meeting (Spain, 1997), Norman was one of a small
number of eminent boron chemists recently retired or close to retirement who were invited
to give an overview of their achievements. However, the primary focus of IntraBoron was
(and EuroBoron remains) the encouragement of PhD students and early-career academics to
present their work, a concept that Norman always strongly supported.
Norman Neill Greenwood 19
Mössbauer spectroscopy
Norman made Mössbauer measurements on more isotopes than anyone else (as far as the
authors are aware). This was not for setting records, but accords with his studies of basic
chemistry and the periodic table—as revealed in his books Mössbauer spectroscopy with Terry
Gibb (2 ) and Chemistry of the elements with Alan Earnshaw (11 ). Both are monumental works.
The five isotopes are the 3d transition metal Fe57 (the most commonly used isotope), Ru99 (a
4d transition metal), Eu151 (a 4f rare earth), Sb121 (Group V) and Te125 (Group VI).
He was selected to be a member of the exclusive group of scientists who had access to
Mössbauer data acquired from the Apollo 11 Mission (in 1969, the first human Moon landing
by Armstrong and Aldrin) and those coming later, Apollo 14 (1971) and Apollo 15 (1971).
He also measured samples of lunar soil brought back by the Soviet Union's (as it was then)
unmanned Luna 16 (1970) and Luna 20 (1972) Moon shots. The Mössbauer spectra showed
the presence of several iron minerals that are found in the Earth's crust (ilmenite, pyroxenes,
olivine and metallic iron), but significantly no ferric compounds, indicating the absence of
oxygen.
As well as his research contributions, Norman was also active in promoting Mössbauer
spectroscopy by establishing the Royal Society of Chemistry's Mössbauer Discussion Group
(sadly now defunct) and getting the International Board for the Applications of the Mössbauer
Effect (IBAME) recognized by IUPAC and the International Union of Pure and Applied
Physics (IUPAP), which assured their sponsorship and funding of the biennial International
Conferences of the Applications of the Mössbauer Effect (ICAMEs); he organized a
memorable international conference at the Royal Institution (1966). After C.J.'s talk, he
pointed out that Michael Faraday (electromagnetic induction) and James Dewar (liquefaction
of hydrogen) had made demonstrations from the same bench.
Norman's contribution to the area was both significant and considerable and his book is
essential reading for those interested in Mössbauer spectroscopy.
Greenwood and Earnshaw: chemistry of the elements
Norman was a pioneer within chemistry academia, and in 1984 an innovative new textbook
written by him and his colleague at the University of Leeds, Alan Earnshaw, was published by
Pergamon Press (11 ). Norman described his approach to writing the book and the philosophy
behind its style in an interview with Brian F. G. Johnson, available on YouTube (https://www.
youtube.com/watch?v=E8lUNZC-bOg). In this clip (story 241 of a series of 252), Norman
confesses that Alan Earnshaw came to his rescue when he realized how long the project was
taking him. Norman explains that he wanted readers to discover that chemistry is exciting
and, in his own words, 'wondrous, even'. He was very aware that judicious presentation of
the chemical information was paramount to the readership if the book were to find its unique
niche in the market. Norman also wanted to distinguish between chemical compounds that
were made once and were only stable under non-ambient conditions, and compounds that were
synthesized on industrial scales. He wanted to make connections to commercial applications
so that his readers could see the relevance of inorganic chemistry.
Eventually, the 1542-page book, entitled Chemistry of the elements , was published and
became an international success. In its preface, Ron Gillespie (McMaster University, Ontario)
20 Biographical Memoirs
says that, whereas most inorganic chemistry texts of the same era placed an emphasis on
theory, Chemistry of the elements confronts the reader with a critical and comprehensive
account of real chemistry. Gillespie points out that students who are destined to be chemists
must possess a thorough knowledge of chemical facts so that they can critically apply theory
to the subject.
Norman and Alan chose to open their text with a chapter entitled 'Origin of the elements.
Isotopes and atomic weights'. The second sentence says: 'At present 107 elements are
known ... ', which immediately makes it clear how much progress has been made in the
time period between 1984 and 2018 in the preparation of the so-called superheavy elements.
In 2018, the periodic table possesses 118 elements, a pleasing achievement as we celebrate the
International Year of the Periodic Table in 2019. Norman would have been delighted to see the
periodic table so extended. The discussion of stellar evolution in the first chapter of Chemistry
of the elements is in stark contrast to the typical opening chapters of inorganic chemistry texts
in the twenty-first century. Most begin with a treatment of atomic and molecular orbitals, and
theories of covalent and ionic bonding. Perhaps the philosophy behind the first chapter of
Chemistry of the elements alone is enough to single it out as a reference book rather than a
text that targets undergraduate or graduate students; opinions on this are mixed. Listening to
Norman talk about his approach to the text, it is clear that he envisaged a didactic text. In
his preface, Ron Gillespie hopes that the book will be the 'standard reference in inorganic
chemistry for both teachers and students for many years to come'. On the other hand, in
a review written in 1985 for the Journal of Chemical Education ( Wolsey 1985), Wayne
Wolsey says that 'it is the opinion of this reviewer that it is not an ideal student text', while
G. Dyer, who also reviewed the text, praises the 'refreshingly different approach' and feels
that Chemistry of the elements will have a 'major beneficial effect on the future teaching
and learning of main-group chemistry especially' (Dyer 1985 ). However, Wolsey hailed
Greenwood and Earnshaw as 'the most significant one-volume inorganic chemistry work
since Cotton and Wilkinson's text, which was first published in 1962' (Cotton & Wilkinson
1962).
The title Chemistry of the elements sets Norman's book apart from other texts in the field,
where the titles Inorganic chemistry ,Advanced inorganic chemistry and Modern inorganic
chemistry are the norm. After the inspired choice of stellar evolution in the first chapter (which
ends with an interesting section headed 'Points to Ponder'), Greenwood and Earnshaw's text
continues in a more traditional manner. The contents are organized following the groups of the
periodic table. Where the first or second element of a group is of particular importance, it is
given a dedicated chapter. Heavier congeners are discussed together. Given Norman's passion
for boron, it is only to be expected that the description of the chemistry of this element is
especially detailed, and examples of borane and carborane clusters abound. Everyone who
knows the first edition will remember the structure of the ferraborane that adorns the front
cover of the book. The organization of each chapter was similar, progressing through natural
occurrence of the elements, commercial extraction and production, physical and chemical
properties, reactivity and a detailed overview of important compounds. As Wolsey pointed
out in his review, the depth of descriptive chemistry was on a par with the likes of J. R.
Partington (Partington 1937 ). Incorporated into the chapters of the d -block metals is coverage
of organometallic and bioinorganic chemistries, giving the text a completeness that satisfied
most readers. Despite the traditional organization of material, features that set Chemistry of
the elements apart were the innovative figures and schemes (even though in monochrome) and
Norman Neill Greenwood 21
the wealth of information on industrial processes and commercial applications of inorganic
chemicals. This information was obviously gathered before the days of the Internet and
Norman explained that it had involved many personal visits to industrial companies and
exhaustive numbers of postal communications.
The great success of the first edition of Chemistry of the elements led to the second edition
being published by Butterworth-Heinemann in 1997 (20). The book remained in monochrome,
but, nonetheless, a new design, page size, cover and contents made the edition fresh and a
must-have for researchers, teachers and students of inorganic chemistry. Even with 13 years
between editions and a simultaneous expansion of the relevant research literature, Norman and
Alan resisted the temptation to expand the book significantly. P. J. Craig, who reviewed the
second edition for Applied Organometallic Chemistry , said that 'the second edition continues
the good work of the first' (Craig 1998). A sign of the times sees this statement in his
review: 'it may not appeal greatly to the CD-ROM-, soundbite-oriented student as it is fairly
traditional in style'. Nonetheless, Craig continues that 'it is an essential (student) possession'.
Translations into several European and Asian languages testify to the success of the text.
In 2006, Norman was excited about the possibility of working on a third edition of
Chemistry of the elements. The publisher interested in developing this project was Elsevier,
and Norman enthused that they had plans for colour graphics and dissemination of the book
through electronic media. Sadly, the third edition never became reality, and Norman died
in 2012. However, Chemistry of the elements lives on. The second edition is now available
electronically through Elsevier's platform, Science Direct (https://www.sciencedirect.com/
book/9780750633659/chemistry-of-the-elements). Individual chapters can be downloaded in
PDF format, making the book more widely and easily disseminated.
Personality, family and activities
Personally, Norman was outgoing, friendly and a reliable supporter of his students, staff and
colleagues and his university departments. At Nottingham, together with Cliff Addison, he
was highly regarded by the staff and undergraduates not only for the excellence of his lectures
but also for his breadth of knowledge. In both Newcastle and Leeds, he energized the newly
formed inorganic chemistry departments.
A dedicated traveller, he had already explored much of his local Australia before leaving
for Europe and when in Cambridge took advantage of the long vacations to explore large
parts of Europe, witnessing much of the devastation caused by the Second World War. In
1951 he married Kirsten (née Rydland) who was a Norwegian. They had met on the London–
Newcastle boat train as Kirsten headed home to Bergen after a year learning English and
Norman was setting out for a holiday to Sweden via Norway. Together with their three
children, Karen, Anne and Linda, they continued to travel extensively. Norman was especially
proud to have fulfilled his childhood ambition to set foot on every continent of the world,
including Antarctica.
Honours and awards
1960 Fellow of the Royal Institute of Chemistry
1966 Tilden Lectureship and Medal, Chemical Society, London
22 Biographical Memoirs
1967 Visiting Professorship, Michigan State University, USA
1973 Visiting Professorship, University of Western Ontario, Canada
1974 Royal Society of Chemistry Medal for Main Group Element Chemistry
1977 D de l'Univ honoris causa, University of Nancy, France
1979 Visiting Professorship, University of Copenhagen, Denmark
1983 A. W. von Hofmann Lectureship of the Gesellschaft Deutscher Chemiker
1984 Liversidge Lectureship and Medal, Royal Society of Chemistry
1985 Visiting Professorship, Wuhan University, China
1985 Visiting Professorship, La Trobe University, Australia
1987 Fellow of the Royal Society
1989 Egon Wiberg Memorial Lectureship, Munich, Germany
1991 Ludwig Mond Lectureship and Medal, Royal Society of Chemistry
1991–93 Visiting Professorship, Toho University, Tokyo, Japan
1992 Foreign Member of the French Academy of Sciences
1993 Royal Society of Chemistry Award for Tertiary Education
2000 DSc honoris causa, Toho University, Tokyo, Japan
Acknowledgements
Norman Greenwood's daughters, Karen, Anne and Linda, provided background information about Norman's early
years in Australia. The photographs, including the portrait, are from the family's collection unless otherwise
stated.
References to other authors
Cotton, F. A. and Wilkinson, G. 1962 Advanced inorganic chemistry. New York: John Wiley & Sons.
Craig, P. J. 1998 Book review: Chemistry of the elements , 2nd edn, N. N. Greenwood and A. Earnshaw.
Appl. Organomet. Chem. 12, 880. (doi:10.1002/(SICI)1099-0739(199812)12:12< 880::AID-AOC755>
3.0.CO;2-C)
Dyer, G. 1985 A review of Chemistry of the elements . N. N. Greenwood and A. Earnshaw. Synth. React. Inorg. Met.
Org. Chem. 15, 1261–1262. (doi:10.1080/00945718508059406 )
Emeléus, H. J. and Anderson, J. S. 1939 Modern aspects of inorganic chemistry . Imperial College of Science and
Technology, London, and D. Van Nostrand Co., New York.
Fialkov, Y. A. and Shor, O. I. 1948 TERMICHESKAYA DISSOTSIATSIYA I ELEKTROPROVODNOST
KHLORISTOGO IODA V RASPLAVLENNOM SOSTOYANII. Zhur. Obsh. Khim. 18, 14.
Partington, J. R. 1937 A textbook of inorganic chemistry, 5th edn. New York: Macmillan.
Wolsey, W. C. 1985 Review: Chemistry of the elements (Greenwood, N. N.; Earshaw, A.). J. Chem. Educ .62, A133–
A134. (doi:10.1021/ed062pA133.2 )
Bibliography
The following publications are those referred to in the text. A full bibliography is available as electronic
supplementary material at http://dx.doi.org/10.1098/rsbm.2019.0015.
(1) 1950 (With H. J. Emeléus) The electrical conductivity of iodine monochloride and iodine trichloride. J.
Chem. Soc. 0, 987–990. (doi:10.1039/JR9500000987 )
Norman Neill Greenwood 23
(2) 1971 (With T. C. Gibb) Mössbauer spectroscopy . Oxford: Chapman & Hall.
(3) 1974 (With C. G. Savory, R. N. Grimes, L. G. Sneddon, A. Davison & S. S. Wreford) Preparation of a stable
small ferraborane, B4 H8 Fe(CO)3 . J. Chem. Soc., Chem. Commun .0, 718.
(4) 1978 (With J. D. Kennedy & D. Taylorson) Mass spectrometric evidence for icosaborane(26). J. Phys.
Chem. 82, 623–625. (doi:10.1021/j100494a027 )
(5) 1979 (With S. K. Boocock, J. D. Kennedy & D. Taylorson) Isomers of B20 H26 : elucidation of the structure
of 6,6 -Bi(nido -decaboranyl) by 11 B-{ 1 H} and 1 H-{ 11 B} NMR spectroscopy. J. Chem. Soc., Chem.
Commun. 2, 16–17. (doi:10.1039/C39790000016 )
(6) (With J. D. Kennedy, W. S. McDonald, J. Staves & D. Taylorson) Isomers of B20 H26 : structural
characterisation by X-ray diffraction of 2,2 -Bi(nido -decaboranyl). J. Chem. Soc., Chem. Commun.
1, 17–18. (doi:10.1039/C39790000017 )
(7) (With J. D. Kennedy, T. R. Spalding & D. Taylorson) Isomers of icosaborane(26): some synthetic
routes and preliminary characterisations in the Bis(nido -decaboranyl) system. J. Chem. Soc., Dalton
Trans. 5, 840–846. (doi:10.1039/DT9790000840 )
(8) 1980 (With S. K. Boocock, J. D. Kennedy, W. S. McDonald & J. Staves) The chemistry of
isomeric icosaboranes, B20 H26 : molecular structures and physical characterization of 2,2 -
Bi(nido -decaboranyl) and 2,6 -Bi(nido -decaboranyl). J. Chem. Soc., Dalton Trans. 5, 790–796.
(doi:10.1039/DT9800000790 )
(9) 1981 (With S. K. Boocock, Y. M. Cheek & J. D. Kennedy) A new route to isomers of icosaborane(26),
B20 H 26 : the use of 115.5 MHz 11 Band11 B-{ 1 H} nuclear magnetic resonance spectroscopy for
the comparison and characterisation of separated isomers and the identification of three further
icosaboranes as 1,2 -, 2,5 - and 5,5 (or 5,7 )-(B10 H13 )2 .J. Chem. Soc., Dalton Trans. 6, 1430–1437.
(doi:10.1039/DT9810001430 )
(10) (With S. K. Boocock, J. D. Kennedy, W. S. McDonald & J. Staves) The chemistry of isomers
of icosaborane(26), B20 H26 : synthesis and nuclear magnetic resonance study of various isomers of
platinahenicosaboranes and diplatinadocosaboranes, and the X-ray crystal and molecular structures
of 7,7-Bis(dimethylphenylphosphine)-nido -7-platinaundecaborane and 4-(2 -nido -Decaboranyl)-7,7-
bis(dimethylphenylphosphine)-nido -7-platinaundecaborane. J. Chem. Soc., Dalton Trans. 12, 2573–
2584. (doi:10.1039/DT9810002573 )
(11) 1984 (With A. Earnshaw) Chemistry of the elements . Oxford: Pergamon Press.
(12) 1985 (With S. A. Barrett, J. D. Kennedy & M. Thornton-Pett) The chemistry of isomers of
icosaborane(26): crystal and molecular structure of 1,2 -bi(nido -decaboranyl). Polyhedron 4, 1981–
1984. (doi:10.1016/S0277-5387(00)86722-4 )
(13) 1986 (With X. L. R. Fontaine, J. D. Kennedy, P. I. MacKinnon & M. Thornton-Pett) Preparation of
[(C5 Me5 )2 Rh2 B17 H19 ]via a degradative insertion from anti -B18 H22 , and a possible mechanism
for anti→ syn macropolyhedral interconversion. J. Chem. Soc., Chem. Commun. 14 , 1111–1113.
(doi:10.1039/C39860001111 )
(14) 1987 (With M. Bown, X. L. R. Fontaine, J. D. Kennedy & P. MacKinnon) The isolation and characterisation
of the 1- and 2-isomers of nido -[(η 6 -C6 Me6 )RuB9 H13 ] – but is the 1-isomer nido or arachno ?J. Chem.
Soc., Chem. Commun. 11, 817–818. (doi:10.1039/C39870000817 )
(15) (With M. Bown, X. L. R. Fontaine, P. MacKinnon, J. D. Kennedy & M. Thornton-Pett)
Organoruthenaborane chemistry. Part 5: products of the reaction between closo -[B10 H10 ] 2− and
[(η 6 -C6 Me6 )ClRuB3 H8 ]. Nuclear magnetic resonance studies and the crystal and molecular
structure of [{ ( η 6 -C6 Me6 )2 Ru2 H4 }RuB10 H8 (OEt)2 ]. J. Chem. Soc., Dalton Trans. 11 , 2781–2787.
(doi:10.1039/DT9870002781 )
(16) 1988 (With M. Bown, T. Jelínek, B. Štíbr, S. Heˇ
rmánek, X. L. R. Fontaine, J. D. Kennedy & M.
Thornton-Pett) Facile pathway-defined fluxional cluster isomerization in ten-vertex closo -2,1,6-
metalladicarbaboranes of ruthenium and rhodium. J. Chem. Soc., Chem. Commun. 14, 974–975.
(doi:10.1039/C39880000974 )
(17) 1992 Taking stock: the astonishing development of boron hydride cluster chemistry. Chem. Soc. Rev. 21 ,
49–57. (doi:10.1039/cs9922100049 )
24 Biographical Memoirs
(18) 1994 Electron-deficient boranes as novel electron-donor ligands. In Coordination chemistry: a century of
progress (ACS Symposium Series, vol. 565) (ed. G. B. Kauffman), pp. 333–345. Washington DC:
American Chemical Society.
(19) 1997 The impact of IMEBORON conferences on the development of boron chemistry. Collect. Czech.
Chem. Commun. 62, 1143–1149. (doi:10.1135/cccc19971143)
(20) (With A. Earnshaw) Chemistry of the elements , 2nd edn. Oxford: Butterworth-Heinemann.
(21) 2002 The concept of boranes as ligands. Coord. Chem. Rev. 226, 61–69. (doi:10.1016/
S0010-8545(01)00433-7)
ResearchGate has not been able to resolve any citations for this publication.
The crystal and molecular structure of 1,2′-(nido-B10H13)2 has been determined by single-crystal X-ray diffraction analysis, thus con
- N. N. Greenwood
The electrical conductivity of molten iodine monochloride passes through a maximum at 40°. The conductivity of solid and liquid iodine trichloride has been measured in the range 70-150°. That of the solid increased rapidly with increasing temperature. There was no marked discontinuity at the melting point. In the molten state there was a maximum in the conductivity-temperature curve at 111°. It was shown that the maximum in the case of the monochloride was probably due to a decrease with rising temperature in the number of ions present. The degree of ionisation in molten iodine monochloride was of the order of 1%. For neither compound was there any indication of a decomposition potential. On prolonged electrolysis of molten iodine monochloride a small back e.m.f. was observed.
-
![Mark Bown]()
- Xavier L. R. Fontaine
- Norman N. Greenwood
- Peter MacKinnon
Reaction between [(η6-C6Me6)RuCl2]2 and K[B6H11] yields a rare example of a 2-metalla nido-decaborane derivative, [2-(η6-C6Me6)-nido-2RuB9H 13], together with an unprecedented 1-ruthena isomer having the same empirical formula but a more open arachno-type structure.
Reaction of [(C5Me5)RhCl2]2 with anti-B18H22 in the presence of base yields, via boron vertex loss, a 19-vertex dirhodanonadecaborane [(C5Me5)2Rh2B17H19] of which the structure has been confirmed by X-ray crystallography; it comprises a 12-vertex nido{RhB11} subcluster and a 10-vertex nido{5-RhB9} subcluster conjoined with a common triangular {B3} face so as to generate an effective syn configuration.
- Simon K. Boocock
- Norman N. Greenwood
-
![John D. Kennedy]()
- Derek Taylorson
The structure of one of the B20H26 isomers formed by thermolysis of nido-decaborane in the presence of tetrahydrothiophen has been shown to be 6,6′-bi(nido-decaboranyl) by means of 1H-{11B} n.m.r. spectroscopy in conjuction with 'partially relaxed'11B and 11B-{1H} n.m.r. spectroscopy; it is the largest neutral borane yet characterised.
- Norman N. Greenwood
- Chris G. Savory
- Russell N. Grimes
- S. S. Wreford
The orange liquid B4H8Fe(CO)3 has been prepared by direct reaction of pentaborane(9) with iron pentacarbonyl and also by the reaction of tetraborane(10) with enneacarbonyldi-iron; spectroscopic evidence shows that the Fe(CO)3 group has replaced the apex BH group in B5H9 and that the compound has structural and bonding affinities with C4H4Fe(CO)3 and C[Fe(CO)3]5.
Source: https://www.researchgate.net/publication/338029674_Norman_Neill_Greenwood_19_January_1925-14_November_2012
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