Methyl- and phenyl-mercury(II) derivatives of 2-mercaptopyridine. Crystal and molecular structure of methyl(pyridine-2-thiolato)mercury(II)

Abstract

The compounds [HgR(L)](R = Me or Ph, L = pyridine-2-thiolate) have been isolated by reaction of HL with methylmercury(II) hydroxide and phenylmercury(II) acetate, respectively. The crystal structure of the methyl derivative has been determined at 190 K. The compound crystallizes in the monoclinic space group P2₁/n with a= 10.834(5), b= 4.206(3), c= 17.144(2)Å, β= 101.91(1)° and Z= 4. Refinement converged to R= 0.036 for 1 676 independent observed reflections. The pyridine ligand is co-ordinated to mercury by the thiolate sulphur atom [Hg–S 2.374(2)Å]. The intramolecular mercury–nitrogen distance of 2.980(5)Å is shorter than the sum of the van der Waals radii. The vibrational spectra of the compounds are discussed. The ¹³C n.m.r. spectra in chloroform and a dipole-moment study in benzene suggests that the secondary mercury–nitrogen interaction is maintained in these solutions.