Synthesis and crystal structures of new palladium–sulfur–nitrogen complexes

The compound S4N4 reacts with [PPh4]2[Pd2X6] (X = Cl or Br) in CH2Cl2 to give a mixture of [PPh4]2[Pd2(mu-S2N2)X6], [PPh4]2[Pd2(mu-S3N2)X4] and [PPh4][Pd(S2N2H)X2]. Reaction of [PPh4]2[Pd2l6] with S4N4 in the same solvent yields an insoluble solid of empirical formula [PPh4][Pd2S6N6l3]. All these reactions were investigated by N-15 NMR spectroscopy using samples prepared from S4 N-15(4). Thermolysis of [PPh4]2[Pd2(mu-S2N2)Cl6] in CHCl3 gives an alternative polymorph (beta-form) of this, whereas photolysis causes the species to decompose. The crystal structures of [PPh4][Pd(S2N2H)Cl2], beta-[PPh4]2[Pd2(mu-S2N2)Cl6] and [PPh4]2[Pd2(mu-S2N2)Br6] have been determined.