THE PREPARATION AND CRYSTAL AND MOLECULAR-STRUCTURE OF THE COMPLEX CIS-PTCL2(RAZOXANE)

Treatment of K-2[PtCl4] with the anti-cancer drug razoxane (3,5-dioxop iperazin-1-yl-propane) in aqueous HCl solution gave the water-insolubl e complex cis-PtCl2(razoxane), which is the first metal complex of raz oxane to have been isolated. The crystal and molecular structure of th e complex confirms that razoxane is present as a bidentate ligand, Pt- N = 2.095(11) and 2.080(9) Angstrom, and was not hydrolysed during com plex formation as was previously observed in the presence of other met al ions. This is also one of the few examples in which platinum is bon ded to a ligand via tertiary nitrogen atoms only. The presence in the complex of two cis chloride ligands, Pt-Cl=2.299(4) and 2.277(3) Angst rom, and square planar geometry around the metal ion is also confirmed . Intermolecular hydrogen bonding between an imide oxygen atom of each molecule and an imide NH group of another results in a sheet-like 'zi g-zag' structure. Crystal data for cis-PtCl2(razoxane):monoclinic, spa ce group P2(1)/c, a=9.165(2), b=16.573(3), c=10.984(2) Angstrom, beta= 114.60(3)degrees, Z=4, R=0.0341, R-w=0.0385. (C) 1998 Elsevier Science S.A.