Complexes of palladium(II) with nucleosides. Preparation and properties of complexes of the type potassium trichloro(nucleoside)palladate(II)

Abstract

The preparation of the monobase complexes K[PdLCl₃](L = nucleoside or pyridine) is described for the first time, in dimethylformamide solutions. The complexes are characterized by elemental analyses, conductivity measurements, i.r. spectra, and chemical reactions. They are unstable in aqueous or acidic solutions. At pH ca. 9–10 the inosine and guanosine derivatives are transformed into dimeric O(6)N(7) chelates. The reactions of K[PdLCl₃] with other nucleosides in water have also been studied and produce 1 : 4 and 1 : 2 complexes of the type [PdLL′₃]Cl₂, cis- or trans-[PdL(L′)]Cl₂, and cis- or trans-[Pd(L – H)(L′– H)], where L′= the same or a different nucleoside to L. The binding sites of these complexes are N(7) of the purine rings, as is revealed by their ¹H n.m.r. spectra.