A NEW CLASS OF PLANAR MIXED METAL-CLUSTERS CONTAINING A [PT3(CO)3(PR3)3] MOIETY CAPPED BY 2 HGX UNITS

The reaction of the clusters [Pt3(mu(2)-CO)3L3] (L = PCy3, PPhCy2, PPh(i)Pr2, and P(i)Pr3) with mercury halides (Hg2X2 and HgX2) gave trigonal-bipyramidal pentametallic clusters of the type [{HgX}2{Pt3(mu(2)-CO)3L3}] which were fully characterized by multinuclear NMR. While these clusters are monomeric in solution, the X-ray crystal structure of [{HgBr}2{Pt3(mu(2)-CO)3(PPhCy2)3}] shows that this compound is dimeric in the solid state and consists of two Hg2Pt3 trigonal bipyramids, each being bonded to a bromine atom on one side and two bridging bromine atoms on the other side. Crystal data are as follows: trigonal space group R3cBAR (No. 167), a = 21.232 (3) angstrom, c = 58.494 (9) angstrom, V = 22836 (3) angstrom 3, and Z = 6. The structure was refined to R = 0.038 (R(w) = 0.044) for 1294 data with I greater-than-or-equal-to 3.0(I).