Hermann J. Becher

Diphenylarsinoderivate des Maleinsäureanhydrids und verwandte Verbindungen. Kristall- und Molekülstruktur des 2,3-Bis(diphenylstibino)maleinsäureanhydrids

The unusual properties of bis(diphenylphosphino)maleic anhydride and similar ditertiary phosphines has prompted the synthesis of analogous arsines and stibines. Bis(diphenylarsino)maleic anhydride,-maleic thioanhydride and-N-methyl maleic imide, bis(diphenylstibino)maleic anhydride (5) and-maleic thioanhydride are obtained as crystalline yellow or red compounds by the reaction of the corresponding 2,3-dichloromaleic acid derivatives with diphenyl(trimethylsilyl)arsine and-stibine resp. The uv/vis spectra and characteristic i.r. bands of selected compounds are given and compared with those of the corresponding phosphines. The strong shift of νC=C to lower wavenumbers observed in all compounds has caused the determination of crystal and molecular structure of5 by x-ray diffraction. Bond distances and angles are given. The complex formation of the new diarsine ligands has been examined by the preparation of Ni-, Cr- and Mo-carbonyl derivatives. As the first organylsulfane substituted maleic acid derivatives bis(phenylthio)maleic thioanhydride,-N-methyl-maleic imide and-maleic acid dimethylester are synthesized and described.

Diphenylphosphinoderivate von Malein- und Fumarsäureestern: Darstellung, Eigenschaften, Kristall- und Molekülstrukturen

The reaction between 2,3-dichloromaleic acid dialkylester (alkyl=CH3 and C2H5) and diphenyl(trimethylsilyl)phosphine, leading to diphenylphosphine substituted esters of maleic and fumaric acid has been studied. With a molar ratio 1:1 of the components 2-chloro-3-diphenylphosphinomaleic acid dimethylester (3) and-diethylester are obtained as colourless crystalline compounds. From a 1:2 reaction however only bis(diphenylphosphino)fumaric acid dimethylester (colourless crystals) and-diethylester (yellow) can be crystallized, the latter in a partially oxydized form. The presence of bis(diphenylphosphino)maleic acid diester in the oily part of the reaction products has been proved by its chelating with Ni2+ and Pd2+ to complexes of the compositionMeCl2·(PP). Pure bis(diphenylphosphino)maleic acid dimethylester (4) could be synthesized by alcoholysis and following methylation of bis (diphenylphosphino)maleic anhydrid. Contrary to this easily chelating and air stable compound the corresponding fumaric acid diesters give no complexes with the metals examined as far and are very sensitive towards oxygen. This sensitivity decreases strongly after oxydation to 2-diphenylphosphino-3-diphenylphosphorylfumaric acid diester, the diethylester of which could be crystallized in pure form.Characteristic vibration bands, uv/vis-absorption and31P-nmr peaks are discussed.The result of X-ray diffraction data of3 and4 are reported and conformation, bond lengthes and bond angles of these molecules are given.