X-RAY CRYSTAL-STRUCTURE OF TETRACHLORO(TRANS-D,L-1,2-DIAMINOCYCLOHEXANE) PLATINUM(IV) COMPLEX - A POTENTIAL ANTICANCER AGENT

Tetrachloro(trans-d,l-1,2-diaminocyclohexane)platinum(IV) complex (tetraplatin or ormaplatin) has been recognized as a potential anticancer agent. We have determined the crystal structure of this compound by x-ray single crystal diffraction. It has a unique space group and rare molecular packing. Parameters are as follows: space group R3cBAR (rhombohedral), a = 26.425(4) angstrom, alpha = 54.50(1)-degrees; V = 11375angstrom3, Z = 36. The coordination about Pt atoms is a slightly distorted octahedron owing to the presence of the geometrically strained five-membered ring (avg. N-Pt-N angle = 82.9-degrees). An intricate network of intermolecular hydrogen bonds holds the crystal lattice together. Three independent ormaplatin molecules surround each water molecule, forming the three shortest A ... B contacts and thus the three strongest hydrogen bonds.