History of Chemistry
Chemistry at Bristol: History
Chemistry has been a distinctive feature of the intellectual mix right from the foundation of University College, Bristol in 1876; one of the first two professors (E. A. Letts) was a chemist who had discovered (in 1872 while in Berlin) a method for synthesising nitriles from carboxylic acids (the Letts Nitrile Synthesis).
Sir William Ramsay, who received the Nobel Prize in 1904 for the discovery of the noble gases (argon, neon, krypton and xenon), was Professor of Chemistry in Bristol from 1880-1887. Sir John Kingman, Vice-Chancellor of the University of Bristol (1985-2001) spoke of how Ramsay “established important Bristol traditions. First, the idea that teaching was best done in an atmosphere of research. Second, that young men and women worked best when they devised and undertook their own experiments. Third, the concept that what was done in academic life should have a relevance to the industrial life of the country”.
Chemistry at Bristol has always been broad in scope. Synthesis across the molecular gamut from organic to inorganic has always been prominent, and has recently moved into materials science and biology. Physical, theoretical and analytical chemistry has been similarly important – notably as applied to gas phase chemistry, colloid science and biogeochemistry.
As in any experimental science the physical facilities for the conduct of chemistry research are vital. At first, Chemistry was located on the top floor of a building in Park Row and consisted of a laboratory, a lecture room, a professor’s room and a store. In 1883, a new building for Science and Engineering was constructed and the chemistry section contained a main laboratory, a lecture room, a professor’s private rooms and some small rooms for lecturers. This was looked upon at the time as model for a small chemistry school.
The UK’s first purpose-built chemistry building in Woodland Road (1910), designed by organic chemist Prof Francis Francis (1904-1936), was regarded as well ahead of its time. In 1965, Chemistry moved to a new building in Cantock’s Close, the design being led by Professors Douglas Everett and Wilson Baker. This represented a major expansion of the School and provided space to bring in much new and then very advanced instrumentation, e.g. NMR, mass spectrometry, and X-ray crystallography and provide a suite of new teaching laboratories.
In the period from 1900 to 1960, a number of individuals arrived in Bristol and defined key strands of the research profile of the School of Chemistry. James W. McBain (1901-1926) was the first Leverhulme Professor of Chemistry – the Leverhulme chair was established to retain McBain who had received an invitation to go to the University of Toronto - and this began the strong Bristol tradition of research in colloid chemistry. He moved to Stanford University in 1926, and then became the first director of the National Chemical Laboratory of India in 1949. During McBain’s tenure, the family of P J Worsley, who had died during World War 1, donated £2000 for the upkeep of what became known as the Worsley Chemical Library, which remains a key resource within the School supporting both teaching and research.
William E. Garner (1926-1954), who had worked with leading chemists Professor P F Frankland and Sir Robert Robinson, was responsible for major advances in the surface chemistry of solids and heterogeneous catalysis. The School’s most prestigious undergraduate class award is named in recognition of Garner’s achievements.
The tradition of synthetic chemistry at Bristol was first defined by Sir Edmund Hirst (1936–1944) who had worked with Haworth on the synthesis of vitamin C, was very prominent in research on carbohydrates.
Hirst was followed as Professor of Organic Chemistry by Wilson Baker (1944-1965), a student of Lapworth and Robinson, who established a team of organic chemists including Sir Alan R. Battersby and W. David Ollis, which contributed widely to natural products and biological chemistry, heterocyclic chemistry, and non-benzenoid aromatics, e.g. biphenylene and meso-ionics like N-phenylsydnone.
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Biphenylene |
N-phenylsydnone |
By 1960 there were two Professors of Chemistry. The Alfred Capper Pass Chair was held by Wilson Baker, head of the department of Organic Chemistry, while Douglas Everett, head of the department of Physical Chemistry, held the Leverhulme Chair. When Gordon Stone became the first head of the department of Inorganic Chemistry, in 1963, a federal structure for the School of Chemistry was established. A fourth smaller department of Theoretical Chemistry was added in the late 1960s under the leadership of Richard Dixon. This structure survived until a unified School of Chemistry (as a single University department) was created in 1990.
In the post-1990 new structure, the previous “Departments” became Sections led by Heads, and the Physical and Theoretical Departments combined to form a single Section.
Physical Section Heads: Douglas Everett (1954-1982); Ron Ottewill (1982-1992); Richard Dixon (1992-1994); Brian Vincent and Michael Ashfold alternately through the 1990s and Mike Ashfold since 2000.
Theoretical Section Head: Richard Dixon (1969-1990)
Inorganic Section Heads: Gordon Stone (1963-1990); Jon McCleverty (1990-1992); Guy Orpen (1992-2001); Selby Knox (2001-3); Nicholas Norman (2003-present).
Organic Section Heads: Wilson Baker (1944-1965); Mark Whiting (1965-1984); Jake MacMillan (1984-1990); Tom Simpson (1990 - present)
Reflecting the developments in chemistry research, the three Sections of the School of Chemistry are currently named Inorganic and Materials Chemistry, Organic and Biological Chemistry, and Physical and Theoretical Chemistry. Until 1990, the heads of the departments took it in turn to act as the formal Head of Chemistry. At various times in the period 1961-1990, there was also a Department of Analytical Chemistry.
Organometallic and Coordination Chemistry
In 1963 F. Gordon A. Stone was appointed as the first Professor of Inorganic Chemistry. This led to the establishment at Bristol of an internationally-renowned centre of excellence in the chemistry of molecular complexes of metals – notably organometallic chemistry, with the potential to provide answers to problems in catalysis, synthetic organic chemistry and also in the development of new materials.
Edward (Eddie) W. Abel, with interests in both main group and transition metal chemistry, played an important part in the early development of this strand of synthetic inorganic chemistry Another strand of the department in this period was structural chemistry, led by Peter Woodward, who set up a crystallographic unit in the School of Chemistry to determine the molecular structure of new compounds in house.
In 1966 Michael Green moved to Bristol and collaborated with Stone, focussing initially on fluorocarbon transition metal chemistry. This led to the discovery of complexes such as [Pt(C2H4)3] - “platinum with wings” (made by John Spencer) - and [Pt(cod)2]. Independently, Peter Timms devised the so-called metal-atom approach - vaporising a metal in vacuo in the presence of a reactive ligand - to such complexes. Timms developed an apparatus so that undergraduates could make -complex compounds like [Cr(C6H6)2] in the teaching laboratories.
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[Pt(η-C2H4)3] |
[Cr(η-C6H6)2] |
[Mo(CO)5Rh2(µ-CO)2(η-C5Me5)2] |
In the early 1970s the organometallic group was further strengthened by the arrival of Neil G. Connelly (1971-2009) and Selby A. R. Knox (1971-2003) bringing knowledge of electron transfer reactions of metal complexes and transition metal cluster chemistry respectively. One of the key discoveries during this time was the linking of alkynes at molybdenum centres, providing an insight into Reppe’s discovery of the nickel-catalysed cyclotetramerisation of acetylene to form cycloctatetraene. Knox established an extensive chemistry of diruthenium species bridged by simple hydrocarbon ligands such CR, CR2, CH=CR2 and C=CR2 Such species were thought to play an important role in the Fischer-Tropsch reaction, an industrial process which enables coal as an alternative to oil as a primary feedstock for fuel and the chemicals industry. In this period the physical inorganic group broadened into spectroscopy and kinetic studies led by Peter L .Goggin and Robin J .Goodfellow, principally investigating the post-transition metals
A major theme in Stone’s later work was stimulated by the earlier studies of the reactions of fluoroalkenes with zero-valent platinum complexes where it was suggested that a Pt=C double bond could behave like an alkene and coordinate to another metal centre. Even a Rh=Rh bond could act as a donor to another metal as in [Mo(CO)5Rh2(µ-CO)2(η-C5Me5)2]. In an extensive series of investigations this led to routes to metal clusters carrying CR and CR2 fragments, thus providing a possible insight into organic reactions at metal surfaces and providing much support for Hoffmann’s “isolobal” hypothesis. The success of the organometallic venture throughout this period depended strongly on the contribution of crystallographers including Judith A. K. Howard (1971-1991), A. Guy Orpen (1979-present) and John C. Jeffery (1983-2008). Orpen's group later developed influential structure-bonding studies, notably re-defining the nature of the metal-phosphine bond and establishing the use of structural databases in coordination and supramolecular chemistry.
Following Stone’s retirement, Jon McCleverty arrived in 1990 and, with Mike Ward, shifted the balance of the department towards coordination chemistry of the transition metals. They initiated fundamental spectroscopic, electro- and magneto-chemical studies of polarisable di-, tri- and tetra-nuclear molybdenum and tungsten complexes,. This led to redox-mediation of both linear and non-linear optical properties of polarisable metal complexes, resulting in the development of near-infrared electrochromic molybdenum-based variable optical attenuators that were comparable at the time to the best alternative attenuator technologies. Collaborating with Belgian chemical physicists Clays and Persoons, hyper-Rayleigh scattering spectroelectrochemistry was developed and this brand new technique was used to study the hyperpolarisability of unstable polarisable species which can only be generated electrochemically in situ.
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A highly-polarisable dinuclear oxotungsten complex capable of existing in a 4-membered electron transfer chain. |
During the 1990s, the process of broadening the inorganic chemistry group towards materials applications (later formalised as the Inorganic and Materials Section) began and this broadening of the research base was pursued. This was reflected in the appointment of Stephen Mann in 1999 and the establishment of the Centre for Organized Matter.
Physical Chemistry
The pre-eminence of Bristol in the field of surface and colloid science was established through the 60s and 70s under the leadership of Douglas H. Everett (1954-1982). He made major contributions to the study of thermodynamics, and in particular to acid-base equilibria, porous media, physical adsorption of gases on solids, adsorption from solution and colloid stabilization. In World War 2, Everett was involved with the Special Operations Executive and wrote a book on this with Fredric Boyce: SOE: The Scientific Secrets (2003).
He was succeeded as head of the department of Physical and the fourth Leverhulme Professor of Physical Chemistry by Ronald Ottewill (Bristol 1964-1992, OBE 1989). Ottewill played a leading role in initiating a highly successful MSc Course by advanced study and research in Surface Chemistry and Colloids. His most famous contributions were in his pioneering work on the controlled synthesis, characterisation and properties of polymer latex dispersions. In particular, he was the first person to apply the new technique of small-angle neutron scattering (SANS) to studying the structure of concentrated latex dispersions. The graph below shows the development of the “structure factor peak” with increasing particle concentration, from which he showed that information about the inter-particle interactions and the radial distribution function of the particles could be deduced.
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SANS results for a concentrated latex dispersion. |
Electron micrograph of the adsorption of small particles onto a large particle of opposite charge. |
The colloid group was further strengthened in the early 1970s by the arrival of Brian Vincent and Terence Cosgrove. Vincent (1972-2007) succeeded Ottewill as the holder of the Leverhulme chair, and was the first to investigate what subsequently became known as, the “depletion flocculation” of colloidal particles in dispersions containing high concentrations of non-adsorbed polymer molecules. His group made the first electrically-conducting polymer latex particles (in 1983) and the first monodisperse, surfactant-free, silicone oil emulsions (in 1994); both of these discoveries have been followed up world-wide. The electron micrograph shows the adsorption of small particles onto a large particle of opposite charge, as a model for molecular adsorption.
Cosgrove (Bristol 1973-present and current Leverhulme Professor of Physical Chemistry) made major contributions to the study of the structure and dynamics of polymer molecules at interfaces. He has pioneered the use of the modern techniques of pulsed-field gradient NMR and small-angle neutron scattering in this area. His experimental work, together with theoretical advances by a collaborating group at Wageningen (Netherlands), formed the core of the first extensive and widely-consulted textbook on the subject in 1993.
Theoretical Chemistry: Molecular Dynamics and Lasers
The smaller department of Theoretical Chemistry was led by Richard Dixon (1969-1996) used spectroscopic and theoretical methods to determine the structure and energetics of unstable free radicals, usually generated in the gas phase by flash photolysis of stable parent molecules. He was joined by Michael Ashfold (1981- present) and together they initiated the use of these techniques, combined with the now available narrow band laser sources and cold molecular beams, to study in detail the molecular choreography of the photolytic act itself in a wide range of molecules. A major advance was the development of so-called Rydberg tagging of fragment hydrogen atoms; a Time of Flight spectrum of such atoms displays individual peaks, which reflect the the population distribution within the partner molecular fragment (usually a transient free radical). This contributed to the international renown of the Bristol Molecular Science Research Group, led by Gabriel Balint-Kurti, which carries out cutting-edge experimental research, combined with advances in the applications of quantum mechanics necessary to interpret new results.
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One striking example concerns the photolysis of NH3 at an ultraviolet wavelength of 212nm. The spectrum shown above indicates that the H-atom comes off perpendicular to the NH3 frame, leaving the NH2 co-fragment spinning with most of the energy trapped in high speed rotation about an axis parallel to the H—H axis (see the right-hand picture above). In a higher pressure gas this retained energy would have a dramatic effect on secondary reactions.
The interweaving of physical chemistry with theoretical work later became formalised in the Physical and Theoretical Section of the School of Chemistry. Reflecting this trend, a computational chemistry group emerged strongly in the 1990s with the appointment of first Neil Allan (and later Jeremy Harvey, Adrian Mulholland and Fred Manby) enabling the group to look outwards and build links with geology, biochemistry and transition metal chemistry among other areas.
Natural Product and Synthetic Organic Chemistry Research
In the 1960s the gibberellins research of Jake MacMillan (1963-1990, elected a member of US National Academy of Science in 1991) came to prominence. MacMillan is the international authority on the physiology and chemistry of the agriculturally-important family of plant hormones, the gibberellins, and his contributions led the field for nearly four decades. He collaborated vigorously with botanists and horticulturalists throughout the world and he has profoundly influenced research on the study of growth control in higher plants.
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Gibberellin GA3 |
GA3 for gardeners |
Effect of GA3 on grape growth |
MacMillan also participated in determining the molecular structure of the GAs and developed gas chromatography-mass spectrometry (GS-MS) methods to identify low abundance GAs in plant tissue. This led to the elucidation of the GA-metabolic pathway, both in the fungus, Gibberella fukikuroi, and in intact seeds, enzyme preparations from seeds and vegetative shoots of higher plants. These metabolic studies made use of stable isotopes and GC-MS in establishing specific steps in the pathway and have now developed towards the identification of the enzymes and their genes of GA biosynthesis.
The influence of biological chemistry in Bristol was given impetus by the return of Tom Simpson (1990-present). His research has focused on natural products and underpinning biosynthetic pathways, particularly the enzymatic processes and genetic control of polyketide biosynthesis.
Tenellin biosynthetic pathways (top); Part of the 1H/15N 2D NMR spectrum of acyl carrier protein (pink and green), the central substrate of polyketide and fatty acid biosynthesis (malonyl transferase) is shown in blue and red.
Polyketides are responsible for the production of many clinically and commercially important antibiotics and other compounds of medicinal and agrochemical significance, and the polyketides group (now Russell Cox, John Crosby, Chris Willis and Matt Crump) at Bristol is internationally recognised for their ground breaking work in establishing the biosynthetic detail of the pathways that Nature uses to produce these compounds.
The importance of biological chemistry was formalised when Organic Chemistry became the Organic and Biological Section within the School of Chemistry. More recently, Dek Woolfson was appointed jointly between Chemistry and Biochemistry, underpinning the importance of the links that exist across these disciplines.
Synthetic organic chemistry, after a relatively quiet period in Bristol, began its renaissance with the appointment of Tim Gallagher in 1993, bringing interests in both methodology and total synthesis and signalling a major investment in the field over the following decade. It was no accident that Gallagher and Neil Connelly (from the synthesis-dominated inorganic group) were both heavily involved in the design and delivery of the Synthetic Chemistry Building in the late 1990s. This led to further, major expansion of synthetic organic chemistry and the appointments of Aggarwal, Davis, Booker-Milburn around the turn of the millenioum.
Organic Geochemistry
The work of Geoffrey Eglinton (1967-1993) led to the founding of the field of molecular organic geochemistry and a vital strand of interdisciplinary science at Bristol with strong links to earth and geographical sciences. He developed new GCMS analytical methods for the study of organic compounds in rocks which has important implications for oil exploration, created molecular yardsticks for palaeoclimate study, and studied aeolian dust in marine sediments. With James Maxwell (1968-1999), he established the Organic Geochemistry Unit (OGU) at Bristol, and developed novel stereochemical markers for tracing the evolution of organic compounds on a geological time scale. Eglinton was among the geologists who studied the moon rocks, and was the only non-American on the Lunar Sample Analysis Planning Team.
Bristol received 105 grams of lunar soil following the Apollo 11 mission and, after scrupulous analysis to avoid contamination, the Eglinton team announced in 1971 that the lunar relics offered no indication of life. Negative results are sometimes very important!
The work of the group in Bristol did demonstrate the presence of methane on the moon, produced by chemical reactions driven by the solar wind and the photo shows Colin Pillinger and James Maxwell handling the Apollo mission moon rock samples.
The appointment of Richard Brereton in 1983 paved the way to the development of a research theme in chemometrics, and Bristol has established an international reputation in this area.
With the appointment of Richard Evershed in 1993, the research portfolio of the OGU broadened to include subject areas such as archaeological chemistry, soil biogeochemistry and geomicrobiology. Now known as the Bristol Biogeochemistry Research Centre, this grouping interacts widely with colleagues in the Schools of Earth Sciences, Geography, and Archaeology, and hosts the Bristol node of the national NERC-funded Life Sciences Mass Spectrometry Facility.
Physical Organic Chemistry: Unusual Organic Molecules
The Bristol brand of physical organic chemistry has its roots in the work of Mark Whiting (1965-1984), who developed syntheses of very long molecules of precisely known length (e.g. C400H802) that provided a “gold standard” for the study of crystallisation and solid state behaviour of polymers. These materials proved so useful to physicists, that his work has been extended since his retirement. Whiting was also one of the first people to study the nucleophilic reactivitiy of transition metal complexes (e.g. [PhFCr(CO)3] and, at a time when “non-classical carbocations” were all the rage helped to define what might be expected from a “classical” carbocation.
The work of Roger Alder (1965-2003), a physical organic chemist, focused on devising and synthesising novel molecules which exhibit remarkable properties and explore new types of valency. He showed that 1,8-bis(dimethylamino)naphthalene (Proton sponge®) is an exceptionally strong base because protonation relieves strain between the NMe2 groups and creates a strong N….H-N+ hydrogen bond. Alder studied special types of bonding between bridgehead atoms such as in the 3-electron bonded and in the 1990s, he was very active during the worldwide surge of interest in “stable carbenes”. It was Alder who demonstrated that aromaticity and pendant rings were unnecessary to confer stability.
The arrival of Guy Lloyd-Jones (1996 - present) provided a very different angle on physical organic chemistry which very much complemented Alder’s contributions and led to studies of organometallic catalysis and mechanism.
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Proton sponge® |
A 3-electron N-N bond |
A stable diaminocarbene |
New Buildings and Doctoral Training Centres
By the 1990s, the need to update and provide additional laboratory facilities, such as many more fume hoods for synthetic chemistry, had become pressing. Professor Selby Knox, then Head of the unified School of Chemistry (prior to 1990 there had been four separate, though linked, departments) oversaw the planning and delivery of a new Synthetic Chemistry Building which opened in 1999.
The SCB cost £17M, of which the Higher Education Funding Council for England (HEFCE) provided £5M, and contained sixteen 12-person research laboratories with 200 fume-hood workstations and separate write-up areas. This represented the very latest in laboratory design, and was achieved by working closely with industry (notably GlaxoWellcome).
Since 2000, these outstanding new laboratories provided the School with a major opportunity to attract a series of internationally renowned groups to Bristol within organic and inorganic synthetic chemistry, such as Varinder Aggarwal, Ian Manners, Kevin Booker-Milburn, and Tony Davis.
In moving synthetic chemistry research to the new building the School of Chemistry vacated most of the East Block of the 1960s building (which became new teaching laboratories for the Faculty of Medical Sciences). In the period 2000-2006, upgrading of the South Block (primarily for physical chemistry research) was achieved through a £12M refurbishment programme funded largely by HEFCE.
In 2005, Professor Guy Orpen, who succeeded Knox as Head of the School, led a successful £5M bid that established Bristol Chemistry as a HEFCE Centre for Excellence in Teaching and Learning (CETL), one of only four (of 74) such centres in all of science and the only one in chemistry. Bristol ChemLabS was born. With an additional University investment of £13M, the complete refurbishment of the West Block was carried out, providing both new research labs (for materials and biological chemistry) and teaching laboratory space. Bristol ChemLabS now not only provides outstanding laboratory facilities to Bristol undergraduates, which are integrated with a totally different approach to practical teaching, but is also the focus for an extensive outreach activity that engages with thousands of school age children nationally, and increasingly internationally, each year.
The establishment in 2009 of two EPSRC Doctoral Training Centres in Synthetic Chemistry and Functional Nanomaterials (the latter in partnership with the School of Physics and housed in the new Centre for Nanoscience and Quantum Information in which Chemistry is a key player) has cemented the School's leading position in the top echelon of UK chemistry departments and as a major player on the world stage.