Peter was a pioneer of materials chemistry, seeking unusual physical properties in inorganic and metal–organic compounds and models to explain them. He played a major role in the development of mixed-valence chemistry, and carried out important and elegant experimental and theoretical work on the spectra, magnetic properties and conductivity of solid, inorganic complexes.
As a young researcher, he gave the first theoretically consistent description of the visible–ultraviolet spectra of vitamin B12 and its derivatives. Later, he put the assignment of inorganic charge-transfer spectra on a more rigorous basis; he correlated structures and physical properties of metal chain compounds and identified the first optically transparent ferromagnetic compounds by combined optical and neutron scattering methods. He also measured and systematised the optical properties of metamagnets.
Peter received awards from both the Royal Society and the Royal Society of Chemistry; the latter named one of its awards in materials chemistry after him. He served many national and international agencies and institutions, both professional and governmental, and held numerous honorary degrees and fellowships.
Professor Peter Day FRS died on 19 May 2020.
Emeritus Professor Chemistry, University of London
Materials chemistry, solid state chemistry
On 'The molecular chemistry of magnets and superconductors'.
On 'Creating and communicating science: the experience of the Royal Institution'.
On 'imants et Supraconducteurs: Nouveau Champ d'Action pour la Chimie Supramoléculaire'.