METAL COORDINATION AND HG-C BOND PROTONOLYSIS IN ORGANOMERCURY(II) COMPOUNDS - SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF THE TETRAHEDRAL COMPLEXES [(NP(3))HGR]-[(CF3)SO3] (NP(3)=N(CH(2)CH(2)PPH(2))(3) R=CH3, C2H5, C6H5)

The tetrahedral complexes [(np(3))HgR][(CF3)SO3] (np(3) = N(CH(2)CH(2) PPh(2))(3), R = CH3, C2H5, C6H5) have been prepared and characterized by MNR spectroscopy (H-1, C-13, P-31, Hg-199),and X-ray crystal struct ure analyses. The reactivity of the methyl and phenyl derivatives towa rd CH3COOH (or CF3COOH) and thiols has been investigated through GC an d/or NMR measurements. In both cases protonolysis of the Hg-C bond occ urs at valuable rates, under mild conditions, with formation of alkane (arene) and [(np(3))HgX][(CF3)SO3] or [(np(3))Hg(SR)][(CF3)SO3] (X = CH3COO, CF3COO; R = C6H5, p-CH3C6H4, C(CH3)3) Kinetics of the acetolys is suggests that, although the coordination of the three phosphorus at oms to the metal center does not substantially change the accepted mec hanism of the protonolysis of the organomercurials, the resulting acti vation of the Hg-C bond strongly accelerates the cleavage reaction. In the case of the reaction with thiols the mechanism appears more compl icated, the basicity of the amino group of np(3) playing a determining role. Crystallographic data are as follows: [(np(3))-Hg(CH3)][(CF3)SO 3] .toluene, 3, Pb2(1)a, a = 34.491(12) Angstrom, b = 12.694(5) Angstr om, c = 11.184(5) Angstrom, Z = 4, R = 0.060, R(W) = 0.059; [(np(3))Hg {S(p-CH3C6H4)}][(CF3)SO3], 9, P2(1)/a, a = 17.509(9) Angstrom, b = 16. 805(7) Angstrom, c = 17.870(8) Angstrom, beta = 113.83(6)degrees, Z = 4, R = 0.067, R(W) = 0.066. In both complexes the metal displays a dis torted tetrahedral geometry, with the nitrogen atom of the tripod liga nd being uncoordinated.