A comparison of the coordination chemistry of Ph₂SNH and Ph₂SNCH₂CH₂CN: the preparation and X-ray crystal structures of [PPh₄]PdBr₃(Ph₂SNCH₂CH₂CN)] and trans-[PdBr₂SNCH₂CH₂CN)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)]Br-2. 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. (C) 2001 Elsevier Science B.V. All rights reserved.