The bidentate chelating agent, 8-dimethylarsinoquinoline. Part I. Four-, five-, and six-co-ordinate complexes of divalent palladium and platinum

Abstract

The chelating agent, 8-dimethylarsinoquinoline has been synthesised, and complexes with palladium(II) and platinum(II) have been isolated and characterised. These complexes fall into three classes: (a) the four coordinated monochelated species M(8-dmaq)X₂(M = Pd or Pt; X = Cl^–, Br^–, I^–, or SCN^–; and 8-dmaq is 8-dimethylarsinoquinoline); (b) the bis-chelates M(8-dmaq)₂X₂(X = Cl^–, Br^–, l^–, or SCN^–), which seem to exist as six-co-ordinate complexes in solution; and (c) the five-co-ordinate complexes [M(8-dmaq)₂X]ClO₄ and [M(8-dmaq)₂L](ClO₄)₂(X = Cl^–, Br^–, or l^–; and L can be a donor ligand, e.g. 4-methylpyridine and pyridine). The compounds [MY₂(γ-pic)](CIO₄)₂(Y = 1,10-phenanthroline or o-phenylenebis(dimethylarsine) and γ-pic is 4-methylpyridine) have also been prepared and are discussed. Oxidation of solutions containing M(8-dmaq)₂Cl₂ gives tetravalent complexes which have been obtained as the perchlorates [M(8-dmaq)₂Cl₂](ClO₄)₂.