Crystal packing and hydrogen bonding in platinum(II) nucleotide complexes:: X-ray crystal structure of [Pt(MeSCH2CH2SMe)(5′-GMP-N7)2]•6H2O

We have synthesised the complex [Pt(CH3SCH2CH2SCH3)(5'-GMP-N7)(2)]-6H(2)O (1). where 5'-GMP is 5'-guanosine monophosphate, and determined its X-ray crystal structure. Pt(II) adopts a square-planar geometry in which the bases are coordinated head-to-tail (HT) in the Delta configuration. The nucleotide conformation in this complex is almost identical to that in the previously reported complex [Pt(en)(5'-GMP-N7)(2)].9H(2)O (2), in which there is outer sphere macrochelation via intramolecular H-bonding between the monoanionic phosphate groups and the coordinated ethylenediamine (en) NH. It is therefore apparent that intermolecular interactions rather than intramolecular H-bonding determines the orientation of the sugar-phosphate side-chain in these Pt(II) bisnucleotide complexes in the solid state. (C) 2002 Elsevier Science Inc. All rights reserved.