PREPARATION, SPECTROSCOPIC PROPERTIES AND THERMAL STABILITIES OF ORGANOMERCURY COMPOUNDS CONTAINING THE BULKY LIGAND (ME(3)SI)(3)C OR (PHME(2)SI)(3)C

Mercury compounds of the types HgR(1)R (R(1) = C(SiMe(3))(3); R = Me, Pr-i, Bu, (t)Bu or Ph) and HgR(2)R (R(2) = C(SiMe(2)Ph)(3); R = Me, Bu , CH(2)Ph or Ph) have been prepared. Those containing R(1) were made b y reactions of the bromides HgR(1)Br with the Grignard reagents MgRX, and those containing R(2) by reaction of HgR(2)Cl with LiR or, for R = CH(2)Ph, with Mg(CH(2)Ph)Cl. Replacement of one R group in HgR(2) by the bulky R(1) or R(2) group leads to a large increase in thermal stab ility, a marked shift in the Hg-199 resonance to lower frequency and a n increase in the coupling constant (1)J(C-13-Hg-199) for the Hg-R bon d. The compound HgR(2)Cl does not react further with LiR(2) in tetrahy drofuran, but with LiR(1) gives HgR(1)R(2); the arrangement of the SiM e(2)Ph groups in the latter in solution in CH2Cl2 at low temperature a ppears to be different from that in the solid.