Professor John Pritchard

John Pritchard died on 28th November 2021. He is survived by his wife, Emily, and two sons, Paul and David. His boys remember a kind and loving father taking them to outings in the forest, or on the tube to museums, galleries or football matches (to Burnley matches when they were in London or to the local Leyton Orient); this to please Paul who was a Burnley fan). Many in the Chemistry and Surface Science communities will remember a quiet and unassuming colleague and friend whose meticulous yet adventurous research has left a substantial legacy, particularly in the application of infrared spectrocopy to molecular monolayers on metal surfaces. He dedicated his life to these two disparate worlds, for example the trips to town with his boys were often prefaced by a brief stop at Mile End to visit the lab at QMC and “check on a few things”. And I, for one, never knew that John had ever been to a football match.

John was born in Tottenham where his father ran a Jewellers shop. Following a move to Hainault in Essex, John grew up enjoying walks in Hainault Forest; his love of the outdoors influenced much of his leisure time throughout his life, through to John and Emily’s eventual retirement in the Yorkshire Dales.

John was a student at Ilford Grammar school, where he was encouraged to take the Imperial College entrance exam. After the exam, John wrote to the College expanding on one of his answers, in which he had been disappointed; this led to a further interview and to a place to read Chemistry in 1950. None of John’s colleagues or students would be surprised that he sent that letter. John continued at Imperial College to work for a PhD under F. C. Tompkins FRS. His thesis title was “The surface potential of gases on metal films”.

While a PhD student, John met a young Yorkshire woman, Emily Walton, on a weekend walking trip on the moors. They were married in 1955 and moved to Southampton where John worked in the Mullard Research Laboratory, investigating methods for extending the life of transistors.

John had told Emily that they would move to Yorkshire “in a year”, but in 1959 he was appointed to a Research Fellowship in the Chemistry Department at Queen Mary College, London University, where he remained for his entire academic career. Drawing on his natural attention to detail and inexhaustible patience, John first built an array of glass ultrahigh vacuum systems plus kit for surface potential measurement, with the help of excellent glassblowing and electronics technicians. As was common in those days, John and all has research group had the glassblowing skills to remove and re-seal reaction cells and carry out minor repairs, while the glassblower worked on much more intricate tasks. Moving to IR spectra in ultrahigh vacuum provided a greater challenge, notably John designed a glass bulb in which metal surfaces deposited on two parallel microscope slides formed a multiple reflection infrared cell, which required the slides to be moved apart for evaporation of the clean metal films and precisely repositioned, while under ultrahigh vacuum. This formed the basis of an experiment to confirm Robert Greenler’s prediction that the strength of IR spectra of molecules on the metal surface depended critically on the angle of incidence of the light. Fortunate, perhaps, that John was the son of a watch and clock repairer.

The 1960s and 1970s saw the emergence of a range of new techniques (mainly involving electron spectroscopy and electron diffraction) for investigating surfaces, which led to the coining of the term Surface Science. John embraced these techniques to record the first infrared spectra of a molecular monolayer on a metal single crystal surface (about 1 cm2 of metal surface area and 1 nanomole of molecular material). The technique, correctly known as Reflection-Absorption Infrared Spectroscopy (RAIRS), is now widely adopted in Surface Science.

John’s colleagues at QMC remember him as a polite, unflappable and kind man, who was an excellent teacher and a very safe pair of hands for any administrative task. He was admired and respected by the generations of his research group and by many collaborators, who will also remember his very dry wit. He was indeed polite and kind, but if, in a research discussion, you were making a conclusion too far, or an unsupportable claim, one glance at his face would set you right.

John was promoted to a Personal Chair in 1978 and in 1985 was awarded the Tilden Medal of the Royal Society of Chemistry, but later suffered a mild heart attack and was not able to deliver his Tilden Lecture. He recovered to continue his work at QMC, by this time as the established Chair of Physical Chemistry, until his retirement in 1990.

After a few years John and Emily moved to Embsay on the edge of the Yorkshire Dales, a little later than he had promised in 1955, but they still had many years to enjoy the beautiful walks. They were settled together in a care home in Sheffield when John died at the age of 89.

I make no excuse for using a cliché in stating that Professor John Pritchard was truly a Scholar and a Gentleman.