D. H. Whiffen

Pioneering spectroscopist

David Hardy Whiffen, chemical physicist: born Esher, Surrey 15 January 1922; Lecturer in Chemistry, Birmingham University 1949-59; Superintendent, Molecular Science Division, National Physical Laboratory 1959-68; FRS 1966; Professor of Physical Chemistry, Newcastle University 1968-85, Dean of Science 1974-77, Head of the School of Chemistry 1978-85, Pro-Vice-Chancellor 1980-83; married 1949 Jean Bell (died 1998; four sons); died Stogursey, Somerset 2 December 2002.

D. H. Whiffen was a spectroscopist interested in the interactions between radiation and matter and the information to be obtained by the development of these techniques. His achievements, to use his own words, "were a mixed bag which arises from wishes for change and novelty". He made significant contributions to determining the dielectric loss in non-polar liquids, identification of characteristic infra-red frequencies, identification of free-radicals in solids using ESR (electron spin resonance) – being one of the pioneers of this work – and several double resonance experiments in ESR and NMR (nuclear magnetic resonance).

David Hardy Whiffen was born in Esher, Surrey, in 1922 and educated at a small boarding school on the cliffs at North Foreland in Kent. At 13 he moved to Oundle School, near Peterborough, where he pursued Classics for his first two years before turning to science in 1937. He was awarded a Scholarship at St John's College, Oxford, being tutored by Sir Harold W. Thompson, and gained a first class honours degree in 1943.

He pursued postgraduate research with Thompson from 1943 to 1949 and was involved initially in the study of the infra-red spectra of petroleum-like materials, using home-made equipment. He then explored the use of microwave radar equipment developed at TRE (the Telecommunications Research Establishment) at Malvern to study the properties of liquids and solids.

Although essentially a practical man, he had a deep understanding and was able to test the predictions of the underlying theory of Peter Debye (the Dutch-American theoretical physicist, who had received the Nobel Prize for Chemistry in 1936 for his work on molecular structure, the theory of dipole moments in liquids and the diffraction of X-rays and electrons in gases).

In 1946-47 Whiffen worked at the Bell Telephone Research Laboratories at Murray Hill, New Jersey, with Debye himself, of Cornell and a consultant to Bell Labs. Working there at the time were five Nobel Laureates. In nine months Whiffen developed a sensitive experimental cell usable over a wide range of temperature. He returned to Oxford and demonstrated that polar liquids exhibited a fundamental small dielectric loss caused by molecular collisions and distortions.

In 1949 he accepted a lectureship at Birmingham University and that year married Jean Bell in Glasgow. All four of their boys were born in Birmingham. Whiffen had intended to turn his attention to gaseous microwave spectroscopy, but this proved impossible and he returned to infra-red studies. By this time the characteristic infra-red absorption frequencies of materials were of major interest and throughout his 10 years at Birmingham a number of his papers dealt with these. He collaborated with organic chemists in their characterisation of sugars and organo-fluorine compounds using these methods.

In Birmingham David Whiffen also became interested in the free radicals, thought to be involved in some polymerisations, and constructed a very early electron spin resonance (ESR) spectrometer to investigate them, obtaining some success with powders and ã-ray irradiated powders. A study by Ubersfeld and Erb then showed that an irradiated crystal of glycine exhibited a spectrum which varied with its orientation in the magnetic field. He rapidly developed the techniques required to further such studies and the theory to interpret the results. This was world-leading research which established his reputation in the field. The paper on glycine, published in Molecular Physics in 1959, was the first of many that identified the structure of free radicals produced in irradiated crystals.

When Sir Gordon Sutherland became Director of the NPL (National Physical Laboratory) in 1956, one of his aims was to create a Basic Physics Division to enhance its research reputation. John Pople FRS, later a Nobel Laureate, became the head of the Division in 1958 and he invited Whiffen to lead the Magnetic Resonance section in 1959. Excellent ESR and NMR facilities and expertise were rapidly developed, partly due to the recruitment of experienced "Brain Drain" scientists from North America. The division rapidly became one of the world's leading NMR and ESR laboratories.

A 9GHz ESR spectrometer was soon constructed and the first paper on the CO2 ion produced by irradiating sodium formate was submitted for publication in November 1960. Many more papers followed on inorganic ions and organic free radicals, giving information on radical structure and internal motions. A second ESR spectrometer operating at 35GHz was developed and, besides complementing the first, was equipped to make very early Endor (electron nuclear double resonance) measurements, a considerable technical triumph at the time.

An Endor study of nitrogen defects in diamond was published in the Proceedings of the Royal Society shortly after Whiffen's election to Fellowship in 1966. Together with Ray Freeman, he also accomplished seminal work on double irradiation experiments in NMR. This was the first of several double and triple resonance experiments used in both NMR and ESR to investigate electron-nuclear and nuclear-nuclear interactions, and the techniques developed were significant to the whole future of NMR.

David Whiffen led an impressive group of researchers at the NPL, many of whom established major reputations of their own subsequently. All benefited from working with someone with a deep understanding of magnetic resonance and whose enthusiasm and insistence on quality and reliability of experimental results were unparalleled. It was a privilege to work with him and to learn from him. Well over 300 publications were written in the nine-year lifetime of Basic Physics Division and 30 years later a reunion party celebrated our indebtedness to him.

During his career Whiffen published more than 190 papers and books. For his infrequent relaxation he played tennis, a mean game of squash and occasionally, croquet.

Following political changes at the NPL Whiffen, by then head of Molecular Science Division, left in October 1968 to become Professor of Physical Chemistry at Newcastle University. There he chose to study microwave spectroscopy and his team developed a source modulated microwave spectrometer which it used to study many gases and vapours. He also attempted, unsuccessfully, to develop a tuneable infra-red source using a semiconductor in a variable magnetic field.

He was Dean of Science at Newcastle from 1974 to 1977 and Pro-Vice-Chancellor from 1980 to 1983. In 1985 he retired to Bridgewater in Somerset.

Ray Cook, Tony Hartland and Keith McLauchlan