195Pt, 1H and 31P PGSE diffusion studies on platinum complexes

The first example of the use of Pt-195 PGSE diffusion data (D values) to recognize the solvent dependence of aggregation of the hexachloroplatinate dianion in Na2PtCl6 (1) and in H2PtCl6 (2) is reported. In water, the ions are separated; however, in methanol the D values suggest ion pairing and/or aggregation. Additional H-1 and P-31 diffusion data for organometallic Pt complexes trans-PtX(Aryl)(L)(2) (where L = PEt3 or PPh3) and Pt(C7H4O2)(L-1)(L-2) (where L-1 and L-2 = a variety of ligand types) reveal that phenyl phosphines afford relatively large hydrodynamic radii r(h). The presence of a substituent on the aryl ligand of PtX(Aryl)(L)(2) does not markedly affect the D values, whereas a substituent of similar size added to a PPh3 group in Pt(C7H4O2)(L-1)(L-2) markedly changes both D and rh values. There is only a small concentration dependence of the D values in PtX(Aryl)(L)(2) on changing from 2 to 10 mm. Copyright (C) 2004 John Wiley Sons, Ltd.