A new homobimetallic arenediyl diplatinum(II) unit as building block for macromolecular synthesis. X-ray crystal structure of [C6H2{CH2NMe2}2-1,5-{PtCl(PPh3)}2-2,4]

Treatment of the diaminobenzene [C6H4{CH2NMe2}2-1,3] (NCN-H, 1) with one or two equivalents of cis-PtCl2(DMSO)2 leads to exclusive formation of the doubly cycloplatinated species [C6H4{CH2NMe2}2-1,5-{PtCl(DMSO)}2-2,4] (3), which upon addition of triphenylphosphine yields the bisphosphine adduct [C6H4{CH2NMe2}2-1,5-{PtCl(PPh3)}2-2,4] (4). The X-ray molecular structure of 4 revealed the presence of highly distorted square planar Pt(II) centers which is caused by close proximity of the two phosphine donor ligands. Complexes of type 3 can be regarded as suitable starting materials for the directional build-up of larger macromolecular structures.