Herbert Marcus Powell FRS (7 August 1906 – 10 March 1991) was a British chemist and professor at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

. Powell presented the idea of a correlation between molecular geometry and number of valence electron pairs in a

Bakerian Lecture The Bakerian Medal is one of the premier medals of the Royal Society that recognizes exceptional and outstanding science. It comes with a medal award and a prize lecture. The medalist is required to give a lecture on any topic related to physical ...

in 1940 with Nevil Sidgwick on

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

. He studied chemistry at

St John's College, Oxford St John's College is a constituent college of the University of Oxford. Founded as a men's college in 1555, it has been coeducational since 1979.Communication from Michael Riordan, college archivist Its founder, Sir Thomas White, intended to pro ...

, graduating with First Class honours in 1928, then continued to work in the Chemistry department in Oxford throughout his career. Powell supervised some of Dorothy Crowfoot's undergraduate training in crystallography. In 1964 he became the first (and only) Professor of Chemical Crystallography, retiring from the university in 1974. He was not a fellow of any college until his 1963 appointment to Hertford College. He coined the term

clathrate A clathrate is a chemical substance consisting of a lattice that traps or contains molecules. The word ''clathrate'' is derived from the Latin (), meaning ‘with bars, latticed’. Most clathrate compounds are polymeric and completely envelop t ...

s for inclusion compounds.

References

{{DEFAULTSORT:Powell, Herbert Marcus 1906 births 1991 deaths British chemists Fellows of Hertford College, Oxford Academics of the University of Oxford Alumni of St John's College, Oxford