Synthesis and characterisation of four-membered ring platinalactam complexes derived from 2-cyanoacetylurea; crystal structure of [Pt{N(CONH2)C(O)CH(CN)}(PPh3)2]

The reactions of cis-[PtCl2L2] [L=PPh3 or L2=dppe (Ph2PCH2CH2PPh2)] with cyanoacetylurea [NCCH2C(O)NHC(O)NH2] and triethylamine gives the platinalactam complexes [H(CN)}L2]. A single-crystal X-ray diffraction study on the triphenylphosphine complex confirms the presence of the four-membered platinalactam ring; the urea substituent is involved in intra- and intermolecular hydrogen bonding, forming a dimer in the solid state.