Reactions of sulphur dioxide with palladium(II) complexes

Abstract

The reactions of sulphur dioxide with the salt K2PdCl4 and the anion [HPd(CO)Cl2]− are described. The complexes were isolated either as salts of Ph4As+ and Ph4P+ cations or as complexes of neutral nitrogen donor ligands (LL). The ligands used were bidentate or tridentate ligands such as 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), o-phenylenediamine (o-phen) and 2,2′: 6,2″-terpyridine (terpy). Reaction of sulphur dioxide with K2PdCl4 in aqueous ethanol gave an ethoxysulphonyl dinuclear palladium anion, [PdCl2(SO3C2H5]22−, which reacted with nitrogen donor ligands giving the previously known palladium complexes, Pd(LL)Cl2. If sulphur dioxide was allowed to react with Pd(LL)Cl2 complexes suspended in aqueous ethanol, sulphato complexes of the formula [Pd(LL)SO4]·H2O were obtained. Reaction of sulphur dioxide with a solution of the anion [HPd(CO)Cl2]− and then addition of nitrogen donor ligands, led to the formation of sulphur dioxide complexes.