Rex E. Richards, 1922-2019

ISMAR mourns the passing of Rex Richards, a pioneer in applications of NMR to chemistry and biology and an ISMAR Fellow. The following tribute was written by Prof. Christina Redfield, one of his colleagues at the University of Oxford:

Sir Rex E. Richards FRS died on July 15th at the age of 96. Sir Rex pioneered the early use of NMR spectroscopy to address problems in chemistry. He was elected a Fellow of the Royal Society in 1959 and was awarded a knighthood for services to NMR spectroscopy in 1977.

Rex Richards studied chemistry at St John’s College, Oxford, completing a B.A. degree in 1945. He completed a doctorate on infrared spectroscopy at Oxford in 1948 working under the supervision of H.W. Thompson. A highly cited paper on ‘Spectroscopic Studies of the Amide Linkage’ arose from this work. Rex Richards was appointed as Fellow in Chemistry at Lincoln College, Oxford in 1947 and continued in this post until 1964 when he was appointed to the Dr Lee’s Professorship of Chemistry and became a Fellow of Exeter College, Oxford. Rex Richards held this Chair in Physical Chemistry until 1969 when he became the Warden of Merton College, Oxford, a post he held until 1984. Rex Richards served as the Vice Chancellor of the University of Oxford from 1977 to 1981.

After completing his doctoral work on infrared spectroscopy in 1948, Rex Richards moved into the new area of nuclear magnetic resonance. His first paper on NMR, published in Transactions of the Faraday Society in 1951 with J.A.S. Smith, is entitled “Nuclear Magnetic Resonance Spectra of Some Acid Hydrates”. In this study crystalline samples of nitric, perchloric and sulphuric acid monohydrates and oxalic acid dihydrate were examined at 90 K to investigate the occurrence and structure of the oxonium ion in the crystalline state of these acids. Figure 1 in this paper shows a block diagram of the home-built apparatus used to collect the NMR data. Radiation at a fixed frequency of 12.2 MHz was taken from a Marconi signal generator. The separation of the Zeeman levels was varied by a small change of the main magnetic field, by means of a small field coil wound on one pole of the electromagnet, until absorption occurred. This first paper exemplifies Rex Richards’ interest in applying NMR to problems of chemical interest but also his understanding of the importance of state-of-the-art equipment, often constructed in-house.

During the 1950s and 1960s Rex Richards published numerous NMR studies on a wide variety of compounds including clathrates, hydrazine salts, borohydrides, substituted benzenes, coals and margarine, initially by proton NMR but later using nuclei including cobalt, thallium, fluorine, platinum and phosphorus. Rex Richards and his group investigated solvent effects and molecular motion, relaxation using spin-echo techniques and the enhancement of proton resonances by dynamic nuclear polarization.

Rex Richards met Martin Wood, founder of Oxford Instrument Company, in 1964 and encouraged him to develop high-homogeneity superconducting magnets that would be suitable for high-resolution NMR. A 1969 paper from Halliday, Hill and Richards describes a home-built NMR spectrometer using a 5 T superconducting solenoid constructed by the Oxford Instrument Company. With co-workers including H.D.W. Hill and D.I. Hoult, Richards’ group continued to investigate the critical factors that affected and limited the signal-to-noise ratio in NMR and worked to improve the available instrumentation. The interaction between the University of Oxford and Oxford Instrument Company, through Richards and Wood, continued for many years and led to the installation of the first commercial 14 T, 17.6 T and 22.3 T magnets for solution NMR in the Department of Biochemistry.

In the late 1960’s, Rex Richards became increasingly interested in the application of NMR to biological problems. He stood down from the Dr. Lee’s Professorship in 1969 when he became Warden of Merton College and at the invitation of Rodney Porter, the Whitley Professor of Biochemistry, Richards moved his group to the Department of Biochemistry.  With collaborators including I.D. Campbell, R.A. Dwek, D.G. Gadian, G.K. Radda and R.J.P. Williams, research in the late 1960’s and 1970’s included studies of enzyme-ligand interactions using proton relaxation enhancement, the observation of tissue metabolites using 31P NMR, the interaction of manganese ions with ATP, and motions of polar head groups in phospholipid bilayers.

In 1969, Rex Richards was instrumental, with others including D.C. Phillips, J.R. Knowles, and R.J.P. Williams, in establishing the Oxford Enzyme Group (OEG) to foster enzyme research and to establish a climate in which collaborative research could flourish in Oxford. This interdisciplinary group brought together expertise in NMR, X-ray crystallography and enzymology. Funding from the Science Research Council in 1970 for “Ultra-high-field NMR spectroscopy” allowed the OEG to purchase a 270 MHz spectrometer (Oxford Instrument Company magnet and Bruker console) which made NMR studies of proteins, including lysozyme, possible for the first time in Oxford.  Rex Richards chaired the Oxford Enzyme Group until 1983.