Bridging bonding mode in a metal–pteridine complex. Synthesis and structural characterization of Pt2Cl4(Hmp)2 (Hmp=4-hydroxy-2-mercaptopteridine)

Reaction of PtCl2 with Hmp (Hmp=4-hydroxy-2-mercaptopteridine) afforded the unique platinum–pteridine complex Pt2Cl4(Hmp)2, in which the Hmp ligand bridges the metal centers through the pyrazine ring nitrogen atom and the sulfur atom in a neutral form. This bonding mode is in marked contrast to the usual O4,N5-chelation mode of the pteridine units found in all the other reported complexes.