Died: September 12, 2021.
JACK D Dunitz, who has died aged 98, was Professor of Chemical Crystallography at the Swiss Federal Institute of Technology (Eidgenössische Technische Hochschule) in Zürich from October 1957 until his retirement in 1990. He is credited with shaping contemporary structural chemistry and was renowned as a teacher and mentor. Universally respected and admired, he transcended generations and remained active well into his 90s.
He will be remembered for his kind and gentle manner, his breadth of knowledge and interests, and his penetrating and infectious curiosity. He was devoid of prejudice and this led generations of young scientists from across the globe to gravitate towards him.
He had a profound impact on the international scientific landscape and will be remembered as an exemplar of scientific excellence: a citizen of the world, but quintessentially Scottish.
Jack Dunitz was born in Glasgow and educated at Willowbank Primary, Hillhead High and Hutchesons’ Grammar. The influence of an excellent chemistry teacher, Donald (“Puggy”) McClennan, clearly had a powerful influence on him and he often said that: “He chose chemistry for me, by making it interesting”.
This gratitude would eventually come to be shared by the wider scientific community, for thanks to Mr McClennan’s aptitude, countless generations have benefited from the Dunitz school.
In mid-1940, Dunitz matriculated at Glasgow University, where his chemistry studies were balanced with his obligations in the 1st Renfrewshire Home Guard. Upon completion of his BSc degree with honours in chemistry, he was assigned to John Monteath Robertson, Gardiner Professor at Glasgow, as a doctoral researcher in the field of chemical crystallography, where he determined the crystal structures of acetylenedicarboxylic acid dihydrate and diacetylenedicarboxylic acid dihydrate.
After his doctoral degree, he moved to Oxford to work with Dorothy Crowfoot Hodgkin (Nobel Prize, 1964), funded by the Carnegie Trust for the Universities of Scotland.
This productive time (1946-1948) culminated in the structural determination of a calciferol (Vitamin D) derivative: it also brought him into contact with the Nobel Laureates Professor Sir Lawrence Bragg (1915 Nobel Prize in Physics, aged 25) and Professor Linus Pauling (1954 Nobel Prize in Chemistry; 1962 Nobel Peace Prize). He would later work with these distinguished scientists.
In 1948, he joined the California Institute of Technology in Pasadena to work with Pauling, whom he regarded as “the greatest chemist of the 20th century”.
This period enabled Dunitz, together with Verner Schomaker, to determine the structure of the cyclobutane molecule by gas-phase electron diffraction.
He returned to Oxford (1951-1953) where he and Leslie Orgel experimentally determined the sandwich structure of ferrocene.
Dunitz and Hodgkin, his former mentor, were among the first to see the now iconic double-helix structure of DNA that had been determined by Watson and Crick.
Professional success was complemented by private happiness in August 1953 when Dunitz married Barbara Steuer at Den Haag in the Netherlands.
The couple had recently celebrated their 68th wedding anniversary.
Upon returning to Caltech, he assisted the biophysicist Alexander Rich in establishing a Laboratory of Structural Research at the US National Institutes of Health, Bethesda, MD (1954-1955).
Following the birth of their first daughter, Marguerite, in 1955 (her sister, Julia Gabrielle, arrived two years later), the family returned to London, where Jack was appointed as a Senior Research Fellow at the Davy-Faraday Laboratory, under the direction of Sir Lawrence Bragg.
The final stage of his professional journey took him to Zürich and the renowned Laboratory of Organic Chemistry at the Swiss Federal Institute of Technology (ETH).
Following an offer from the institute’s director Professor Leopold Ružicka (Nobel Prize in Chemistry, 1939), the family relocated to Zürich in October 1957. In the ensuing decades, Dunitz firmly established X-ray crystallography as an indispensable method for structural analysis.
This led to breakthroughs in the structure and reactivity of medium-ring compounds, ion-specificity of biologically important ionophores, polymorphism and the establishment of structure-energy relationships.
Dunitz is perhaps best known for the so-called Bürgi-Dunitz angle, which is universally taught in undergraduate chemistry courses, and for his pioneering work on reconciling the static behaviour of crystals with the dynamic behaviour of reacting molecules in a broader sense.
His standing in the scientific community is reflected by the impressive list of accolades that he received, including visiting professorships and lectureships at universities and institutions in America, Japan, Israel, Canada, England and Spain.
He received, amongst other awards, the Centenary Medal of the Chemical Society, London, Tishler Award, Harvard University, Paracelsus Prize, Swiss Chemical Society, Buerger Award, American Crystallographic Association, and the Arthur C Cope Scholar Award of the American Chemical Society.
In 1990, he received the Gregori Aminoff Prize from the Royal Swedish Academy of Sciences.
In 1974, he was elected as a Fellow of the Royal Society. He was a member of several learned societies, among them the Royal Netherlands Academy of Sciences, the European Academy of Arts and Sciences, the American Academy of Arts and Sciences and the American Philosophical Society. His honorary doctorates included one from Glasgow University.
Jack Dunitz enriched the lives of those with whom he interacted. He was a giant of 20th century science, where his passion and impact continued to manifest themselves long after retirement. His legacy lives on through the countless students and researchers whom he influenced.
In his autobiography, La Primavera, he wrote: “I do not regret a minute of it. If I had another life I would be happy to live it along much the same lines as I have lived this one”.
He is survived by Barbara, Marguerite and Julia, six grandchildren and eight great-grandchildren, his sister, Joan Sellyn, and extended family in Zürich, Graz, London, Glasgow, Canada and the US.
Professor Ryan Gilmour