A comparison of the coordination chemistry of Ph2SNH and Ph2SNCH2CH2CN; the preparation and X-ray crystal structures of [PPh4][PdBr3(Ph2SNCH2CH2CN)] and trans-[PdBr2(Ph2SNCH2CH2CN)2], the first fully characterised complexes of a N-substituted sulfimide

Reaction of excess Ph2SNH (1) with [PPh4]2[Pd2Br6] results in the formation of homoleptic [Pd(Ph2SNH)4]Br2. In contrast the analogous reaction of the N-substituted sulfimide Ph2SNCH2CH2CN (2) with [PPh4]2[Pd2Br6] only results in the formation of trans-[PdBr2(Ph2SNCH2CH2CN)2] (3) even if the ligand is present in large excess. Lowering the reaction ratio to 2:1 (ligand: dimer) allows isolation of [PPh4][PdBr3(Ph2SNCH2CH2CN)] (4). Compounds 3 and 4 constitute the first examples of fully characterised complexes of N-substituted sulfimides and X-ray crystallography confirm the ligands to be bound to the metal through nitrogen; although the nitrile end groups of the substituents have the potential to bind to metals, no evidence for this is seen in these particular systems.