| Citation | Challenger, Frederick (Leeds). Ph.D. (Gottingen), D.Sc. (Birm). Professor of organic Chemistry, University of Leeds. Investigated organo-derivatives of bismuth and thallium; applications of thiocyanogen and cyanogen triselenide; effect of groups contqining mercury, etc., on orientation; new isomeride of thiophthen resulting rfrom work on suplphur compounds of shale-oil; mechanism of formation of organic acids by moulds; methylation of arsenic, selenium and sulphur by 'P. brevicaule', arsenites and selenates giving trimethylarsine and dimethylselenide, alkylarsonic acids giving methylated alkylarsines, whilst alkyl derivatives containing the disulphide link give mercaptans and methylated alkyl sulphides. Identified the much-discussed gas of Gosio as trimethylarsine, and realised the biochemical asymmetric synthesis of laevorotatory malic acid from fumaric acid by the agency of 'Aspergillus Niger'. |