The synthesis and characterization of several new bis(1-alkenyl)platinum(II) complexes have been carried out. The structure of cis-[Pt(dppp)((CH2)6CH{double bond, long}CH2)2] has been determined by X-ray crystallography. The stability and reactivity of the compounds, cis-[PtL2((CH2)nCH{double bond, long}CH2)2] (n = 3 or 4 and L2 = 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)ethane (dppe), L = PPh3) is strongly dependent on the nature of ligand systems. It is found that the insertion of carbon monoxide into the metal-carbon bonds of the platinum alkenyl complexes is possible. Other reactions including transmetalation, intermolecular alkenyl migrations, oxidative addition of methyl iodide are described and the thermal decomposition of the bis(alkenyl) complexes are also reported. © 2007 Elsevier Ltd. All rights reserved.