Metallacyclic platinum(II) bis(sulfonamides)

A series of metallacyclic platinum(II) bis(sulfonamido) complexes have been synthesised by reaction of cis-[PtCl2L2] [L=PPh3 or L2=1,5-cyclo-octadiene (cod)] with the sulfonamides [RSO2NHCH2CH2NHSO2R, RSO2NHCH2CHMeNHSO2R or RSO2NHC6H4NHSO2R; R=Ph or p-C6H4Me] and Ag2O. The products have been characterised by NMR spectroscopy, electrospray mass spectrometry, elemental analysis, and for the complexes [(SO2Ph)}(PPh3)2] and [(SO2Ph)}(cod)], by single-crystal X-ray structure determinations. In both of these complexes, one of the amido nitrogen atoms has the expected approximately planar geometry, but the other nitrogen atom is surprisingly distorted towards a tetrahedral geometry. The more pyramidal nitrogen has a higher trans-influence in the solid state, reflected by a shorter PtN bond, and longer cyclo-octadiene PtC bond length trans to this nitrogen.