STABILITY IN SOLUTION OF (CHLOROMETHYL)PALLADIUM(II) COMPLEXES - X-RAY STRUCTURES OF IPHENYLPHOSPHINE)CHLORO(CHLOROMETHYL)PALLADIUM(II) ANDRIPHENYLPHOSPHINE)CHLORO(CHLOROMETHYL)PLATINUM(II) AND COMPARISON OF THE RELATIVE STABILITIES OF ANALOGOUS PALLADIUM AND PLATINUM CHLOROMETHYL COMPLEXES CONTAINING PHOSPHINE-LIGANDS

The stabilities to storage in CDCl3 solution (both in the absence and presence of air) of a series of chloro(chloromethyl)palladium(II) comp lexes of neutral olefinic, sulfide, amine, and phosphine ligands have been investigated. The decomposition rates and types of products forme d depend upon the nature of the ligands. Three types of reactions invo lving the CH2Cl moiety were found: (i) oxidation to formaldehyde, (ii) formation of ylide complexes, and (iii) coupling to ethene and propen e. Since the phosphine complex trans-[(Ph(3)P)(2)Pd(CH2Cl)Cl] (9) prov ed to be much more stable to storage in solution than its Pt analogue (17), we have compared their X-ray structures. Crystals of 9 (C37H32Cl 2P2Pd) are monoclinic, space group P2(1)/n, with 4 molecules in a cell of dimensions a = 12.361(5) Angstrom, b = 22.714(4) Angstrom, c = 12. 328(4) Angstrom, and beta = 111.36(3)degrees. Compound 17 (C37H32Cl2P2 Pt) is isomorphous with 9, with cell dimensions a = 12.332(2) Angstrom , b = 22.784(3) Angstrom, c = 12.344(1) Angstrom, and beta = 111.32(1) degrees. Both structures were refined by full-matrix least-squares cal culations on F; the final R values are 0.024 for both structures (for 5763 and 6621 reflections, respectively). The possibility that differe nces in the M-CH2-Cl distances in 9 and 17 may reflect their relative tendencies to form carbene complexes by heterolysis of the CH2-Cl bond is discussed.