Preparation and solution behavior of diphosphinepalladium nitrite complexes

摘要

Diphosphinepalladium nitrite complexes of the type [Pd(NO2)(2)L-2] (L-2 = dppm, dppe, dppp) have been prepared by treatment of [PdCl2(CH3CN)(2)] with silver nitrite, followed by addition of the appropriate diphosphine. The nitrite complexes are fluxional in solution at 298 K, but on cooling to 220 K signals due to three species could be detected. These have been assigned to the N-bonded, the O-bonded, and the mixed coordination compounds. Treatment of [PdCl2(dppe)] with two equivalents of TlPF6, followed by addition of (NaNO2)-N-15, produced [Pd((NO2)-N-15)(2)(dppe)], whose P-31 NMR spectrum allowed identification of the three isomers. The analogous platinum complex [Pt(NO2)(2)(dppe)] exists as a single isomer, which is static at 298 K, and a (NO2)-N-15-labeling experiment indicated that it contains N-bonded nitrite ligands. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 24]