Ronald Drayton Brown AM, FAA (1927–2008) was born in Melbourne and had a distinguished scientific career spanning more than sixty years. He was an outstanding, internationally respected researcher in the fields of theoretical chemistry, microwave spectroscopy and galactochemistry, publishing more than 300 scientific papers, three books and three patents. He had the unique distinction of being the first professor appointed to the newly established Monash University in 1959. As Foundation Professor of Chemistry and Head of Department he had the vision, leadership skills and commitment to establish a Department that was to become one of the finest in Australia. He was a mentor to many staff and students. His legacy will shape the direction of Monash chemistry for many years.
Ron Brown died on 2 November 2008 in his eighty-second year. He was the founder of the Chemistry Department at Monash University and guided its destiny for more than thirty years, establishing for it an international reputation as one of Australia’s finest schools of Chemistry. He had a lifelong dedication to research and was an inspirational leader to all who were fortunate enough to be influenced by him. His expertise, passion for teaching excellence, wide knowledge of scientific issues and unbounded enthusiasm rightly earn him recognition and the respect of the international scientific community. His professional career was characterized by several stages, highlighted in each by excellence in scientific achievement. He was an accomplished and keen competitive sportsman with strong family ties. Ron (or RDB as he was known to many) was recognized for his distinguished contribution to the Australian community as an educator and researcher by his appointment as a Member of the Order of Australia in the 2002 Queen’s Birthday Honours (Fig. 1).
Ronald Drayton Brown was born in Melbourne on 14 October 1927 and died there on 31 October 2008. His parents were William Harrison Brown and Linda Drayton Brown, both born in Melbourne. His father was a postal officer, ending his career managing the inquiry desk at Melbourne’s Central Post Office. Ron was an only child and his mother rather discouraged him from making friends or having local children visit and play. He was, however, encouraged to do well at school and in sport, and medicine was identified as a possible career. His mother had musical talents—she played the piano very well. His father was an intelligent man, and both he and his wife were fine singers. In the 1920s and ’30s, singing at home with friends ‘around the piano’ was a popular custom. Ron himself inherited a fine singing voice.
Ron’s father was an outstanding athlete in his youth and represented Australasia (Australia and New Zealand) in many track and field events. He was Australasian champion at a number of distances and held the record for the mile and three miles. Ron himself was not suited for long distance running—he had asthma problems as a youth—but excelled in cricket, in sprinting, in the long jump, the hop, step and jump, and especially, in tennis, table tennis and badminton. By the time he went to London in 1950, he was good enough at badminton to receive a blue for this sport from the University of London. He also became a member of the Surrey badminton team. He continued with this game on return to Australia and in the early 1960s was president of the Victorian Badminton Association. In a 1995 interview as part of the ‘Australian Oral History Project’ of the National Library of Australia, Ron confessed that the only ‘hero’ he might have worshipped as a child was not a scientist or a mathematician but the footballer Jack Dyer. His family had a history in Australian Rules football—his grandfather had played for Richmond and his parents used to go to the matches every Saturday and take Ron with them.
In this same interview, Ron said that his mother clearly indicated that she felt that study and scholarly achievement were important if one was to have a respectable subsequent career. Asked about his possible religious views, he said he had no belief in a personal God. His parents were religious in the Methodist tradition, but at Sunday School Ron became impatient with the biblical stories. He could not really believe them and rebelled against going to services; but he did believe strongly that the universe was governed by rational principles which it was possible to discover by systematic investigation.
Ron admitted to a rather unhappy childhood, especially at primary school where he was often bullied. Secondary school at Wesley College was a lot better—he became interested in cricket, tennis and football, in reading, and in going on picnics. During the war years of 1942 and 1943, the Wesley College precinct was taken over by the Australian Army Ordnance Corps, and the Wesley students moved to Hawthorn to become the guests of Scotch College. The Wesley boys used the classrooms in the afternoons and the Scotch boys in the mornings. Ron found the Scotch College library to be a treasure house, especially for books on astronomy. Ron and his parents lived with his maternal grandparents in the suburb of Prahran. His interest in the stars was initiated not by his parents but by his grandparents, who quizzed their young grandson when sitting outside the house on hot summer nights.
Ron was exceptionally talented. He had won a scholarship to Wesley College; he was dux of the school and topped the state-wide matriculation examinations in his final year. Ron subsequently had a brilliant record at the University of Melbourne, graduating with first class honours in 1946 with the degree of Bachelor of Science. He shared the Exhibition in Chemistry and the Dixon and Cuming Scholarships.
During his third year as an undergraduate student at the University of Melbourne, he was treasurer of the table tennis club. One day he found two girls playing table tennis who had apparently not paid their subscriptions so he felt bound to raise the matter with them. In an interview recorded earlier in 2008 for the Australian Academy of Science’s archives, he described one of the girls (Florence Catherine Mary Stringer, known to all as Mary) as ‘gorgeous’. Mary’s father was Frank Stringer, a Melbourne man. The other side of that story is from Mary who has said that she and a girl friend decided to join the table tennis club because it had lots of attractive young men in its membership (Fig. 2).
Ron and Mary married prior to departing for London in 1950. This very happy marriage lasted to Ron’s death in 2008. Their first son, Ronald Frank Drayton Brown, was born in London (26 December 1952), while two further children were born subsequently in Melbourne—David William Drayton Brown (1 December 1954) and Penelope Drayton Brown (20 November 1957).
While still undergraduates, Ron and Mary became keen skiers, and this interest became an important part of their family life. When living in London they had skied in Austria. On return to Melbourne they joined the Edelweiss ski lodge at Mount Hotham. In later years, they regularly shared a skiing holiday in Snowmass, Colorado, with Professor Ray Martin and his family. Ray Martin was subsequently Vice-Chancellor at Monash. Ron continued skiing until seventy-two years of age. In the 1950s and ’60s, Ron and Mary and the family took up sailing, mainly in a Mirror dinghy as did so many of their friends and colleagues. The RDB Mirror was subsequently passed on to John Swan and his family.
Like many of his generation, Ron was given a Box Brownie camera as a child and quickly became a keen amateur photographer. Just before their marriage in 1950, he and Mary bought a cine camera to record the wedding ceremony and that interest developed into a life-time of making travel-type family cine films, with equipment of professional quality.
During 1947–1949 Ron undertook research for the MSc degree at the University of Melbourne under the supervision of Dr. F. N. Lahey on the spectroscopy of acridone alkaloids. He graduated in 1949, again sharing the Exhibition and the Dixon MSc Scholarship. The title of his thesis was ‘A Study of Certain Alkaloids by Physical and Theoretical Methods’. In 1949 he was appointed Senior Demonstrator in the Chemistry Department. In a Monash publication (Brown 2005) Ron gave a historical account of his growing interest in (and mastery of) theoretical calculations in chemistry. In 1949 he had joined the Faraday Society and in a copy of the Society’s Transactions he had come upon an article by Charles Coulson and Chris Longuet-Higgins that described the use of Hückel molecular orbital theory to calculate bond lengths and other properties of conjugated aromatic hydrocarbons. There were no staff members in either Chemistry or Physics at Melbourne who knew anything much about molecular quantum mechanics and molecular orbital (MO) theory. Ron found he could decipher Coulson’s article and repeat his calculations without having much grasp of the theory of molecular orbitals. He persevered by teaching himself about matrices and determinants, and computing eigenvalues, ‘slogging through’ the texts of Pauling and Wilson, and Eyring, Walter and Kimball. These were the only textbooks on chemical quantum mechanics that were available in the period immediately following the Second World War. At this time there were no programmable digital computers available in Australian universities. All his calculations were done by hand with electrical desk calculators with no memory facilities. The results of each arithmetical operation had to be copied to a worksheet and then re-entered on the keyboard for the next operation.
He thus somewhat accidentally entered the field of π-electrons and their use in developing a crude theory of reactivity via such quantities as charge densities, free valencies and localization energies. He was able to persuade his MSc supervisor that this was worthwhile because he would apply the theory to try to understand the ultraviolet spectra of the acronycine-type alkaloids! He did do some MO calculations on the energy levels of the π-electrons in acridone, but then became fascinated by the possibility of predicting the properties such as charge distribution and chemical reactivity of simple molecules starting only with the appropriate Hückel matrix (an array of zeros and ones). He focused on the non-benzenoid conjugated hydrocarbons, for which the calculations indicated a non-uniform electron distribution. This in turn meant that these hydrocarbons would have substantial polarities, that is, sizeable dipole moments. To the classical organic chemist, this was rank heresy. Ron was thus stimulated to learn how to measure dipole moments, and by a fortunate coincidence, Professor Ray le Fèvre had established a group of physical chemists at Sydney University with expertise in this field.
A visit to Sydney followed. Ron’s first thought was to measure the dipole moment of azulene, but a long and difficult synthesis would have been required. Le Fèvre was interested in the electronic structure of the pharmaceutical antipyrin and suggested that if Ron could prepare some 3-phenylisoxazole-5-one and bring it to Sydney, he would teach Ron how to measure dipole moments. This transpired, and a paper resulted . One of the five authors, Ivan Wilson, subsequently became a staff member at Monash. That visit to Sydney also gave Ron the opportunity to meet and discuss his theoretical interests with Ian Ross, then a graduate student of David Craig. Ron commented that they were all very isolated working in Australia in those days.
Ron had the workshop at Melbourne construct a dipole moment machine, and struggled with synthesis of the azulene hydrocarbon, C10H8. He had just seen a first pyrolysate with an intense blue colour (presence of azulene) when a paper (Wheland and Mann 1949) arrived, reporting the measurement of the dipole moment of azulene, which those workers had purchased from a firm in Switzerland. He had the satisfaction of knowing that the dipole moment was substantial (about 1 Debye)—hydrocarbons could indeed be polar. This activity was the first step in a transition to a new phase in his research career.
In 1950 Ron was awarded an Australian National University travelling fellowship, but was not required to return to the ANU after completing his PhD. He resigned his Senior Demonstrator position at Melbourne and elected to go to the Department of Physics at King’s College, London, to work with C. A. Coulson on theoretical problems such as the effect of dielectric media on electronic spectra. By the end of 1950 he had already published fifteen papers based on his Melbourne work. In 1951 Ron learnt that he had been awarded the Rennie Memorial Medal by the Royal Australian Chemical Institute, and in 1952 he became an Associate Member of the Institute. He graduated PhD from the University of London in 1952. His thesis title was ‘Wave Mechanical Treatment of Organic Reactions with Special Reference to the Diels-Alder Reaction’. Rather than researching the topic suggested by Coulson, his thesis was largely a summary of some twenty published papers describing the work he had done earlier in Melbourne and published in the period 1950–1952 on theoretical calculations of chemical structure and reactivity for a range of unsaturated, non-benzenoid hydrocarbons. He was entirely self-taught in quantum chemistry and the necessary mathematical techniques, and had done this work without any outside help or supervision. In this same year he was invited by the Centre National de la Recherche Scientifique to be Visiting Lecturer in Theoretical Chemistry at the Sorbonne in Paris. The lecturers for the two previous years had been Professor D. P. Craig (a fellow Australian) and Professor C. A. Coulson.
Ron recalled that in 1950, Coulson’s group in the Physics Department at King’s College consisted of several young theoretical physicists and applied mathematicians. Perhaps now the most famous of these is Peter Higgs, after whom the Higgs Boson is named. This fundamental particle, which gives mass to all bosons, is hotly sought after in particle accelerators. The person most famous at that time in the department was the Professor and Head of Department, John Randall, who, with Henry Boot, invented the cavity magnetron that we all now have in our domestic microwave ovens, but that was invented as the war-time generator of the microwaves used in radar. Others to become famous were Maurice Wilkins (Nobel prize in medicine, 1962, shared with Watson and Crick) and Rosalind Franklin, whom many think should also have shared that prize. She was in a laboratory adjacent to the one Ron shared with Higgs and the others.
In 1952–1953 Ron was an Assistant Lecturer at University College (UC), London, working with Sir Christopher Ingold, an outstanding pioneer in the electronic principles of organic chemical reactions. At this time he became aware that there was very little quantitative information about the chemical and physical properties of molecules that could be compared with the theoretically predicted properties, so as to judge the reliability of the calculations. He was fortunate to have many discussions with a visiting American scholar, Al Matsen, famous for demonstrating that the whole of quantum mechanics could be formulated without any reference to electron spin, or indeed the spin of any particle (Matsen 1992). Matsen drew Ron’s attention to the new technique of microwave spectroscopy, which was starting to provide a wealth of data that would provide good tests, and to a lecturer, Jim Millen, who was building a microwave spectrometer at UC. Ron became involved in some of the assembly work. In later years, microwave spectroscopy became Ron’s major interest.
At UC, Ron took over David Craig’s room, David having left to return to Australia, and he inherited Ron Nyholm’s lecture course in the chemistry of coordination compounds. This was an area of chemistry to which he had never been exposed. Professor Ingold felt very strongly that all of chemistry was one subject and that any of the staff could be called upon to teach anything in the undergraduate syllabus. Ingold also felt that the pursuit of a research problem might take you to any part of chemistry—you should then be ready to inform yourself and go ahead. At UC Ron also met John Ridd who had learnt of Ron’s prediction of the mechanism of diazonium coupling to imidazole. A collaboration ensued, and Ron’s suggestion was fully confirmed .
Ron and Mary were planning to make a life in the United Kingdom, but early in 1953 he received a lengthy telegram from the University of Melbourne, saying that they had an urgent need for a staff member to take on a particular teaching role in the Chemistry Department. To accept was a difficult decision. Ron went to see Sir Christopher Ingold about the offer. Ingold’s advice was that a return to Melbourne would be disastrous— a retreat to a backwater. He urged Ron not to take the job—it would be suicidal! But Mary’s father had died while they were away and she was concerned about the health of her mother. Ron’s concern for Mary and his strong belief that Australia would be a better place for a growing family prevailed, so they returned to Melbourne. Ron did not share Ingold’s view that Australia would be a graveyard for science. He was flown back from London, very uncommon in those days when sea travel was the norm, to take up an appointment as Senior Lecturer in the Department of Chemistry, significantly above the grade for his age and experience.
Ron’s first PhD student was Ian Bassett, son of the well-known engineer Sir Walter Bassett. The research consisted of some MO calculations and some basic quantum mechanical improvements to the established methods. Subsequent students included Bruce Coller and Michael Heffernan. The class of MO calculations employed were so-called π-only calculations that were essentially elaborations of the semi-empirical self consistent field (SCF) MO method described by Pariser, Parr and Pople (PPP) in 1953. This approach treated explicitly only the electrons in the π-orbitals, with the electrons in the underlying sigma-orbitals being handled implicitly. The method involves the iterative solution of a set of linear equations (the Roothaan equations) that converge on a set of molecular orbitals and π-electron densities. This specifies the π-electron distribution and the related electronic energy levels of the molecule. The converged solution is termed a ‘Self-Consistent Field’ (SCF) solution.
As this work progressed, Michael Heffernan and Ron had developed by 1958 the ‘Variable Electronegativity Self-Consistent Field’ (VESCF) MO method in an attempt to overcome some recognized deficiencies in the reliability of results from the PPP method. In the VESCF MO method the effective nuclear charge on each atom (equivalent to its electronegativity) is made a continuous function of the π-electron density at that centre. Thus the π-electronattracting power of a given atom varies during each cycle of the iterative calculation leading to the SCF solution. The VESCF method proved to be, for the subsequent decade, the most reliable theoretical predictor of electric dipole moment values in conjugated molecules. Surprisingly, it showed that there was only a minor contribution from the polarization of the underlying sigma-bonds in conjugated molecules, even where adjacent atoms had very different electronegativity values (as in the C-O bond). Dipole moments were found to be dominated by the π-electron densities combined with the unsymmetrical charge distributions of atoms having lone-pair electrons.
Ron and a new PhD student, Richard (‘Dick’) Harcourt, decided in 1958 to investigate the nature of the weak central bond in N2O4. It was a widely held view at that time that this bond, like almost no other, involved only π-electrons, with no underlying sigma-bond. However, when theVESCF method was applied to N2O4 assuming such a bonding arrangement, results were obtained that were inconsistent with the observed properties of the compound. This led to the development of an all-valenceelectron MO procedure—the first for a polyatomic molecule that used fully asymmetrized determinantal wave functions and included all two-electron integrals. Brown and Harcourt showed that the central N-N bond in N2O4 is weakened by delocalization of lone-pair sigma-electrons from the oxygen atoms—a new concept in bonding . It became apparent subsequently that the all-valence-electron method used by Ron Brown and Dick Harcourt, just for this N2O4 bonding investigation, was broadly the same as another approximate all-valence-electron MO method being developed at the same time by John Pople’s group. This method, applied by Pople’s group from its outset in 1965 to many different molecules (but not N2O4) was the very widely recognized Complete Neglect of Differential Overlap (CNDO) method.
Dick Harcourt transferred to Monash University with his supervisor and in July 1963 became the university’s first PhD graduate.
Ron’s theoretical chemistry research work up to 1959, and that of his students, had involved extensive numerical calculations conducted using electromechanical calculators. These calculators had no memories, so all intermediate results had to be transcribed, and extensive checking to eliminate manual errors was essential. A typical MO calculation would take many weeks to complete. Digital computation was still in its infancy, although Bruce Coller did complete some limited MO calculations using Australia’s first programmable digital computer CSIRAC. With the Council for Scientific and Industrial Research (CSIR) decision that computing research was outside its purview, this machine had been transferred from its home at the Radio-physics Laboratory at the CSIR in Sydney, to the University of Melbourne, where it formed Australia’s first academic computing facility.
Ron had a strong interest in teaching and was recognized for his lucid, well organized and inspirational lectures. Ron is now recalled by past students at Melbourne as a highly popular chemistry lecturer who also was notorious for sporting a necktie, dating from his undergraduate days, decorated with a depiction of the testosterone molecule. With Tom O’Donnell at Melbourne he made an educational film on the use of semi-micro equipment in chemical analysis and research. A copy of this film is still in existence, but the technique unfortunately seems to have vanished from the chemistry syllabus. In 1955 he published, also jointly with Tom O’Donnell, a Manual of Elementary Practical Chemistry (Melbourne University Press) that became a standard text for more than twenty years. He later published two other textbooks, Atomic Structure and Valency in 1966 (Jacaranda Press) and Valency (Springer-Verlag) in 1978 with co-authors Michael O’Dwyer and Jay Kent.
Early in 1959, while still a Senior Lecturer at Melbourne, Ron made some enquiries about a Chair of Chemistry at the University of Western Australia, and was placed on a shortlist of two. The final decision went to the local candidate, but the University of Western Australia then offered Ron a Readership. Ron informed his head of department about this, and twenty-four hours later he received a matching offer of a Readership at Melbourne directly from the Vice Chancellor, which he accepted! Then on 25 March of that year he applied for the Chair of Chemistry at the newly created Monash University in Melbourne and was successful.
Ron Brown was the first professor appointed to Monash in 1960 and was the Foundation Professor of Chemistry and Chairman of the Department of Chemistry, positions he held with great distinction until 1991. He moved in 1992 to a Research Chair in Chemistry for his final year. Indeed, he was technically the first person appointed to the staff of the university, even before the first Vice Chancellor, Sir Louis Matheson. According to a 1993 minute of the Academic Board recording his retirement, ‘he has a historical position in the growth of Monash that can be matched by few Professors’. He played a major part in defining the structure of the original Bachelor of Science degree and in the growth of the Faculty of Science, as well as laying the foundations for the strong Department of Chemistry that he helped to create.
In 1985, a Silver Jubilee celebration was held and the lectures were published by the department as Twenty Five Years of Chemistry at Monash (Rae 1985). Ron Brown’s talk was entitled ‘Reminiscences of the Early Days at Monash Chemistry’. In this he revealed that in the original plan for creating Monash University, it had been suggested that if appointments were made during 1959 and construction was started by 1960, the university should be ready to take students by 1964. Amazingly, this statement, which was on the last page of the plan, was lost from the stapling, so that the date 1964 disappeared. The Interim Council then assumed that it ought to be possible to start teaching in 1961, and this was achieved. However, it meant that very intensive activity was needed to get things together in time. There were no buildings on the proposed site except for a house that later became the Vice-Chancellor’s residence, so for the first several months of 1959 Ron worked under an arrangement with the University of Melbourne and occupied a room there, and made his first appointments—Doug Ellis as laboratory manager and Miss Connie Jones as his first secretary. In 1960 the builders moved on to the site at Clayton to start the first construction: ‘In the beginning, there was mud—and more mud’. The Vice-Chancellor arranged for a group of huts to be put on the site near his residence and those early on the site were allocated rooms in these. With un-insulated galvanized iron roofs, these became exceedingly hot in the late summer and early autumn of 1960. The very resourceful groundsman—Paddy Armstrong—attempted air conditioning by means of a jet of water from a hose. Ron was always very proud, and deservedly so, of his contribution to the establishment and growth of a major new chemistry department within the Australian university system.
Ron’s influence on the types of courses and the provision of research facilities was very great and he shared this with other professors appointed during his term. Bruce West (later part-time Pro-Vice-Chancellor) and John Swan (also Pro-Vice-Chancellor and subsequently Dean of Science) were also foundation professors in his department, while Roy Jackson and Asbjorn Baklien joined him subsequently.
When asked in an interview in 1995 what he considered to be the major achievement of his professional life, Ron said: ‘creating a chemistry department out of nothing’. He explained that:
the second decade of my career was heavily engaged in creating a chemistry department from nothing, and a university and a faculty of science from nothing. Because I was the first person appointed to Monash University I became involved in the entire business of creating a new university. That is, helping to draw up the statutes and regulations of the professorial board, the faculty of science, as well as supervising the building of all chemistry buildings; in fact, designing or partly designing them. Appointing or finding and appointing staff of all different kinds and even thinking of how you equip an empty building with the bits and pieces that you need in order to conduct chemistry. It sounds trivial but it was a gigantic undertaking.
At the Professorial Board, Ron’s opinions were always considered of importance in discussions of issues that were of significance to the University as a whole. His impact on the growth of teaching and research in Chemistry at Monash and more broadly in Australia was substantial. Monash was fortunate to have had such an eminent academic among its initial founding members.
Ron’s contributions to the organization of Australian and international science were also very notable. He was elected a Fellow of the Royal Australian Chemical Institute in 1963. He was President of the Victorian Branch in 1963–1964 and received the Institute’s Masson Memorial Scholarship Prize in 1948, the Rennie Medal in 1951 and the H. G. Smith Medal in 1959. In 1965, at the age of thirty-eight, he was elected a Fellow of the Australian Academy of Science (AAS). He served two terms on the Academy’s Council (1971–1974 and 1976– 1980) and was Vice-President, Physical Sciences (1972–76) and Secretary, Physical Sciences (1976–1980). He was Chairman of the Academy’s National Committee for Chemistry. He was also chair of the Science Policy Committee and a member of the subcommittee on Chemical Education. In 1973, on behalf of the AAS he was a member of the Australian delegation that visited China at the invitation of the Chinese Academy of Sciences.
He served on the International Union of Pure and Applied Chemistry as a member of the Bureau and of its Executive Committee, the Division of Physical Chemistry and the Spectroscopy Commission. In this last role he co-ordinated the Working Party on Theoretical and Computational Chemistry of the Physical Chemistry Division in a project for the preparation of a comprehensive listing of acronyms used in theoretical chemistry .
The International Astronomical Union (IAU) appointed him, in 1982, to a panel of international consultants to advise on the desirability of establishing a new commission on bioastronomy. Subsequently, he served as a member of the organizing committee of IAU Commission 51 (Bioastronomy) 1982–1997 and was its President from 1991 to 1993.
A devoted advocate for the abolition of tobacco smoking, he served for many years on the research grants assessment committee of the Anti-Cancer Council of Victoria.
From his earliest work in theoretical chemistry, Ron Brown had recognized that the most reliable experimental data for molecular structures and electric dipole moments came from the gas-phase measurements provided by microwave spectroscopy. However, molecules of particular significance in the testing of methods of theoretical chemistry were deemed to be too inconvenient for study by established microwave spectroscopy groups. Such molecules were highly reactive or difficult to vaporize.
During 1961–1962 klystron microwave oscillators and ancillary frequency stabilization and measurement equipment manufactured in the USA were purchased. The newly appointed electronics officer at Monash Chemistry was directed to use circuit diagrams from the scientific instrument literature to begin the construction of klystron power supplies and a high-voltage square-wave generator to be used as a Stark modulator in the planned spectrometer. The Monash Chemistry mechanical workshop staff undertook the construction of a waveguide absorption cell 3-m long, also following published drawings and descriptions.
Throughout his career Ron clearly delighted in international travel whenever appropriate. In 1964 the Brown family accompanied Ron on an extended lecture tour to the USA and Canada as a Carnegie Fellow—they travelled there by ship but, as was the growing custom, returned by aeroplane. As he visited various microwave groups, Ron transmitted back to Monash any tips and expertise that he gleaned. The two groups most helpful in this regard were Bill Gwinn’s at Berkeley and Cec Costain’s, which was part of Gerhard Herzberg’s spectroscopic laboratories at the National Research Council in Ottawa. When Ron left Ottawa he was presented with a humorous farewell gift of a formal ‘Licence to Operate a Microwave Spectrometer’ signed by Cec Costain and Gerhard Herzberg. This licence noted the condition that it would become invalid if Ron failed to publish a report involving his own microwave spectroscopy within the next five years. Ron proudly displayed the framed licence in his office for many years. This was the real start of his interest in this branch of chemistry.
On his return to Monash in 1964, Ron formally established the Monash microwave laboratory. This involved the design and building of very sophisticated equipment. In 1964 Frank Burden, a recent PhD graduate from Jim Millen’s microwave spectroscopy laboratory at University College, London, was appointed as a Senior Teaching Fellow. Ron had briefly worked with Jim Millen as an unpaid helper when they both were starting their academic careers at UC in 1952.
During 1964 the performance of the microwave spectrometer and its electronic subsystems was tested and refined, primarily by Frank Burden, employing the well-studied calibrant molecules, formaldehyde, SO2 and OCS. By early 1965 the spectrometer was deemed ready for the observation, analysis and structural interpretation of hitherto unstudied microwave spectra. Peter Godfrey, who had been studying as an undergraduate while employed part-time as Ron Brown’s research assistant since November 1961, and who had collaborated with Frank Burden in setting up the new spectrometer, began in 1965 to study the microwave spectrum of the heterocycle selenophene as his BSc Honours research project. This compound was chosen largely because its substitution reaction chemistry was being studied by Alan Humffray at the University of Melbourne at this time. Humffray had developed a suitable synthesis set-up for this extremely malodourous compound, and he and Michael Heffernan, the latter since 1961 a lecturer at Monash with a focus in NMR spectroscopy, had measured and published its NMR spectrum in 1963. The microwave spectral measurement, assignment and analysis was completed by around June 1965 and was written up in Peter Godfrey’s BSc Honours research report. It was subsequently published in 1968 .
During 1965 Frank Burden was working on software, written in Sirius Autocode, to permit the prediction and analysis of microwave spectra on the rather primitive Ferranti Sirius computer that was the Monash Computer Centre’s first digital computer. The acquisition around 1966 of a much more powerful CDC 3200 computer, which supported programming in FORTRAN, greatly assisted the subsequent analysis of microwave spectra. Ron, with a clear interest in computation related to both theoretical chemistry and microwave spectroscopy, helped to guide the development of the Computer Centre’s facilities as chair of the university’s Computing Committee throughout its first decade.
Almost certainly through Ron’s close teaching collaboration with fluorine specialist Tom O’Donnell while a Senior Lecturer at Melbourne, he went to Monash with a keen interest in fluorine chemistry From 1962 he attempted, with a new PhD student, Guido Pez, to synthesize and characterize sulfur monofluoride. Two isomers, FSSF and SSF2 seemed to be possible. The plan was to investigate the structure of any product molecules by microwave spectroscopy. The research required novel fluorine-resistant materials, and with the helpful advice of Tom O’Donnell, much experience was gained in the construction and use of monel metal vacuum lines, teflon swage-lock pipe fittings and kel-F vacuum valves. Eventually an efficient synthetic method was discovered and a mixture of FSSF and SSF2 was produced. The two isomers were characterized by infrared spectroscopy but the report of the microwave spectroscopy of these species was ‘scooped’ in 1963 by the Harvard microwave group, several years before Ron’s first microwave spectrometer was ready. However, Ron retained some interest in fluorine chemistry, and the apparatus and techniques developed in Guido Pez’s research were put to use in 1965 by another PhD student, Ian Bowater, to produce the compound seleninyl fluoride OSeF2. This work resulted in Ron’s first microwave spectroscopy publication, in 1967, reporting the newly measured and analysed microwave spectrum.
For the first six years of microwave spectroscopy at Monash, Ron chose all the research problems that were to be investigated. The guiding criterion was that they should bear directly on significant aspects of valence theory also amenable to calculation via MO theory. In this way the reliability of the MO calculations would be challenged by the measured properties from microwave spectroscopic studies. Of particular interest were the electronic charge distributions as reflected by the electric dipole moments in conjugated organic molecules, including both hydrocarbons and heterocycles. In the case of nitrogen heterocycles it would also be possible, via analysis of nitrogen nuclear quadrupole hyperfine splitting of the rotational transitions, to measure the electric field gradient at the nitrogen nucleus.
Most of these valence theory watershed problems involved either or both very challenging experimental and spectral theoretical requirements. Almost without exception, other microwave spectroscopy groups had chosen to focus on less wide-ranging problems and showed little interest in testing valence theory. Rather they undertook microwave spectroscopy as a research study in its own right of the quantum mechanics of molecular vibrational rotational interactions. Highly reactive, short-lived compounds were avoided, as was the complexity of the hyperfine splitting in molecules containing multiple nitrogen atoms or the spin-rotation interaction in those containing unpaired electrons.
The theory of microwave spectra in molecules with electron and multiple nuclear spin interactions were undertaken under Ron’s supervision by PhD students Peter Godfrey and Graeme Blackman. Several years’ reading in the area of Racah algebra and the theory of irreducible spherical tensors led to significant advances in the capability of the Monash group. Blackman’s work on multiple nuclear quadrupole hyper-fine structure led to the first computer program that could handle a molecule with up to four quadrupolar nuclei. Publications followed over the period 1967–1973 of the microwave spectra, with hyperfine analysis, of nitrogen-containing compounds selenadiazole, triazole and cyanogen azide N-C-NNN. Godfrey’s treatment of the rotational spectra of asymmetric-top molecules having the possibility of unpaired electrons plus an unlimited number of nuclei with non-zero spin, was applied by PhD student Ian Gillard to analyse the microwave spectrum of the stable free radical NF2.
RDB had been fascinated from his earliest contact with theoretical chemistry by MO-theory predictions that certain nonbenzenoid conjugated hydrocarbons would have substantial electric dipole moments. This was certainly counter-intuitive for most organic chemists of the 1940s. When, as a MSc student, Ron gave a seminar on his early MO calculations at Melbourne, it was perhaps not unreasonable on hearing Ron’s prediction that azulene would be quite polar for the then head of organic chemistry, Professor Bill Davies, to assert: ‘Brown, I bet you 10 to 1 that if you could measure it you would find it to be nonpolar’. From that moment onwards Ron put much effort into making that measurement. However, he was beaten to this objective by a measurement in solution in 1949, and then by a more reliable microwave spectroscopy measurement by the ETH Zürich group in 1965 (which reported a significant dipole moment of azulene of 0. 80 D). Notwithstanding this disappointment in failing to get there first, in 1965 there remained two significant non-benzenoid hydrocarbon compounds that had yet to be prepared, let alone measured. They were the benzene isomers fulvene and 3, 4-dimethylenecyclo butene. Improving on a preparation method from the literature involving flow-thermalisomerization of 1, 5-hexadiyne, a sample of the unstable reactive compound 3, 4dimethylenecyclobutene was generated, primarily by efforts of a Senior Teaching Fellow, Alan J. Jones, recently appointed by Ron. The team of Ron, Frank Burden, Alan Jones and Senior Teaching Fellow Jay E. Kent, a spectroscopist newly recruited from Washington State University, then measured and analysed the microwave spectrum, including the electric dipole moment .
The thermal rearrangement of 1, 5hexadiyne was known to produce small amounts of the other benzene isomer of interest, fulvene. Jay Kent investigated this situation with the aim of producing a more substantial yield of fulvene. He found that by increasing the reactor temperature by several hundred degrees and employing a work-up with preparative gas chromatography, useful quantities of purified fulvene could be produced. Measurement of the fulvene microwave spectrum and dipole moment by the team of Brown, Burden and Kent followed, leading to a publication in September 1968 . It was a salutary compliment to the largely independent developments in microwave spectroscopy technology made by the Monash team that one referee of this publication challenged the manuscript on the grounds that it was technically impossible, with currently available detectors and amplifiers, to detect the microwave spectrum of a molecule with such a low dipole moment as that reported (0. 44 D).
Of particular interest at that time was the reliability of the newly developed, and very much more computationally intensive, semi-empirical all-valence-electron CNDO/2 MO method of Pople and Santry, compared with the π-only VESCF method of Brown and Heffernan, then almost a decade old. In the case of 3, 4-dimethylenecyclobutene, both methods have predictions that are within 0. 1 Debye unit of the experimental value, while for fulvene, CNDO/2 overestimates the dipole moment by 0. 45 D and VESCF by 0. 23 D. For the hydrocarbon azulene that had originally stimulated Ron’s interest in theoretical chemistry, CNDO/2 overestimates the dipole moment by the quite unsatisfactory error of 2. 4 D, while VESCF overestimates it by 0. 53 D.
Ron collaborated widely, but quite strategically, in his research. Important collaborators were the organic chemists in the department (especially Frank East-wood, Roger Brown, Gabrielle McMullen and Pat Elmes), who contributed significantly in the preparation of propadienone, butatrienone and tricarbon monoxide. Pat Elmes became a full-time synthetic chemist within the microwave group. Before these particular collaborative efforts, the spectroscopists had achieved several triumphs in this area—the work on the benzene isomers and inorganic fluorine compounds can be cited.
Other notable achievements by the Monash microwave group were the first ever vapour-phase spectrum of an amino acid glycine in 1975 (Fig. 3), the identification and characterization of a new oxide of carbon, tricarbon monoxide (C3O), in 1983 (Fig. 4), and the structure of the hydrogen isocyanide (HNC) molecule in 1975. Measuring the microwave spectrum of the simplest amino acid, glycine, presented immensely challenging experimental problems that had defeated earlier workers. Success was achieved in 1975, although the compound’s presence in interstellar clouds remains to be demonstrated conclusively. A new procedure for the observation of microwave spectra of relatively involatile materials using a supersonic nozzle was developed. This technique enabled the group to determine accurately the structures of several key biological molecules. With the development in 1988 of the Stark-modulated free-jet microwave spectrometer, it became possible to measure the spectra of other amino acids (alanine), a vitamin (nicotinamide), neurohormones (phenylethylamine, amphetamine and histamine) and nucleic acid bases (uracil, cytosine, thymine and adenine).
In 1971 Ron’s interest in astronomy led to the study of interstellar molecules via laboratory microwave spectroscopy coupled with the direct use of radio telescopes to detect molecules in outer space. He persuaded the CSIRO and groups in America and Sweden of his credentials as an astronomer. Ron’s research group, working independently and also with radio astronomy collaborators, had considerable success in discovering interstellar molecules based upon ‘molecular fingerprints’ determined through laboratory measurements. The successes included thioformaldehyde (1971); methanimine (1972); methyl for-mate (1975); HN13C (1976); vibrationally excited cyanoacetylene (1976); DNC (1977); H15NC (1977); vibrationally excited acetonitrile (1983); C3O (1984); NH3 maser; propynal (1988); and C2O (1991). The convergence of Ron’s interests in theoretical chemistry, microwave spectroscopy and radioastronomy culminated in his important contributions to the new field of galactochemistry.
Ron was quick to recognize the implications from the observations of interstellar molecules for the development of theories for the origin of life. He wrote and spoke extensively on this topic [168, 176, 186, 195, 198, 204, 205, 231, 267, 286, 300].
In October 1978 he was invited to participate in a Study Group of the Pontifical Academy of Sciences, on contemporary ideas regarding the origin of life .
In the early 1980s, Ron prepared a series of advanced lectures to chemistry majors that he hoped to publish as a book. The overall title was to be From Ylem to Life. His purpose was to present an account of our present understanding of the evolution of the universe from a very early stage to the present, focusing on two themes. One theme was to trace the production of the chemical elements, to explain how it is that we encounter such a rich collection of all the chemical elements on the surface of the Earth. Chemists should be interested in why we have such an extensive chemistry to study rather than just hydrogen mixed with a modicum of helium, so characteristic of the stars. The second theme was to explore the processes that might lead to locations in the universe favourable for the emergence of living things, including the formation of the requisite building blocks of life—amino acids, nucleic acids and carbohydrates. These lectures covered not only a wide spectrum of chemistry, but important parts of astrophysics, particle physics, cosmology and earth sciences. A copy of these ten lectures given to one of the authors has been placed in the Basser Library at theAustralianAcademy of Science. The word ‘ylem’ means ‘primeval fireball’—the starting point of the universe according to the ‘big-bang’ model. Unfortunately, the lectures were never published.
Ron Brown was always willing to contribute to problems and interests outside the university and his personal research. He gave much time to the Australian Academy of Science, the International Union of Pure and Applied Chemistry, the International Astronomy Union, the Anti-Cancer Council of Victoria and, in earlier times, the Royal Australian Chemical Institute. He was consulted on chemical matters by the Victorian Government and by industry. On the personal side he had a great love of travel, especially when combined with skiing or yachting holidays. He played competitive and social tennis and cricket to an advanced age, and was an exceptional family man, giving much time and affection to his children and grandchildren.
A Festschrift, ‘Valence Electrons, Molecular Shapes and the Origin of Life’, was held at Monash University on 2–4 February 2005 to honour Ron’s contributions to chemistry. One of the speakers was Dr Alan J. Jones, one of his former students. His contribution was subsequently published (Jones 2005). We quote from this article:
It is difficult to provide a synopsis of Ron’s work that will do justice to the magnitude of the contributions that he made during a very active working career. His publications (some 295 papers) encompass about 22 different areas of chemistry from natural products to galactochemistry and the origins of life, but the underlying theme throughout this work is distinguished by efforts to explore electronic structure by whatever means possible, always complementing experiment with theory or vice versa, and challenging the horizons of conventional thinking, e.g. , exploring molecules in space. Over those years, about 120 co-workers were associated with Ron, and most of those were graduate students in his or affiliated research groups at Monash.
It was in 1959 that I first met Ron Brown as my first-year Physical and Inorganic Chemistry lecturer. He delivered lucid inspiring lectures to the honours stream at Melbourne. He was always impeccably dressed in the latest tailored suits with not a lab coat in sight. Such was the lot of a theoretical chemist. His enthusiasm for chemistry was infectious. As an aspirant honours student I visited Ron Brown in his newly constructed office in 1961, gum boots at the ready, but it was a decade later in 1971 that I joined his department as a Queen Elizabeth II Fellow and remained as a staff member for twelve years until 1983. His commitment to scientific excellence was a great inspiration to me.
I left school in 1940 and spent four years in the war-time chemical industry before enrolling at Melbourne University after completing night-time Diploma studies in chemistry at the then Royal Melbourne Technical College. I first met Ron there in 1945, in second-year classes in chemistry, physics and mathematics. I was immediately in awe at his abilities—his remarkable grasp of these and many other subjects— and his sporting prowess. The very wide range of his many publications bears testimony to his intellectual gifts. We became friends, and later colleagues at Monash University. I feel honoured to be a co-author of this Ronald Drayton Brown memoir.
I first met Ron Brown in 1961, at a job interview for a position as a part-time laboratory assistant at Monash. It was my plan to build upon my just-completed Diploma of Applied Chemistry from Swinburne with a more research-orientated degree from Melbourne or Monash. It was good timing— Monash was expanding and such a position was possible there, as research assistant in Ron’s newly completed spectroscopy laboratory. During 1962–1963 I explored and operated the marvellously novel NMR, IR and UV equipment as they were unpacked and set up. Although strongly tempted by research studies in physics, I ultimately opted for honours and PhD studies with Ron Brown in the first years of microwave spectroscopy at Monash. Following an overseas postdoctoral stint, I returned to Monash in 1971 to join Ron in research involving both laboratory microwave spectroscopy and radio astronomy in the new research field of interstellar molecules. There followed a long and fruitful collaboration, often involving Ron’s clear delight in international travel to obscure destinations. The special combination of his brilliant intellect and comprehensive knowledge, clever strategic instinct, personal charm that could inspire unreasonable efforts from his co-workers, and his unswerving loyalty to his research team will be my enduring memory of Ron. I am very grateful too for the warm friendship that we shared throughout our many years of collaboration.
This memoir was originally published in Historical Records of Australian Science, vol.21, no.2, 2010. It was written by:
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