The molybdenum-mercury bond. A multinuclear (¹H, ¹³C, ³¹P, ⁹⁵Mo and ¹⁹⁹Hg) n.m.r. study of (η⁵-C₅H₅)(CO)₂LMoHgX [L = CO, P(OMe)₃ and PPh₃; X = Cl, Br, I, S₂COEt, S₂P(OEt)₂, S₂CNEt₂ and Mo(CO)₃(η⁵-C₅H₅)] complexes and the crystal and molecular structure of (η⁵-C₅H₅)(CO)₃MoHgS₂CNEt₂

Abstract

The nature of the molybdenum-mercury bond has been studied by means of i.r. and multinuclear n.m.r. spectroscopies on complexes of the type (η⁵-C₅H₅)(CO)₂LMoHgX [L = CO, P(OMe)₃ and PPh₃; X = Cl, Br, I, S₂COEt, S₂P(OEt)₂, S₂CNEt₂ and Mo(CO)₃(η⁵-C₅H₅)]. The results indicate the strong covalent character of the Mo-Hg bond. The chemical shifts of ⁹⁵Mo resonances were found in the range from -1706 to -1939 ppm and those of ¹⁹⁹Hg ones in the range from +236 to -1107 ppm.

The structure of (η⁵-C₅H₅)(CO)₃MoHgS₂CNEt₂ has been determined; P2₁/2, a 12.012(5), b 8.206(3), c 17.037(4) Å, β 92.58(3)º, Z 4, R 0.045. Mo-Hg distance is 2.714(3) Å.