Synthesis, characterization and molecular structures of monomeric selenolato complexes of mercury with nitrogen-containing chelating ligands

Abstract

Intramolecularly stabilized divalent mercury selenolates of empirical formula Hg(SeR)(2) [R = 2-Me(2)NCH(2)C(6)H(4) 1, (S)-2-Me(2)NCHMeC(6)H(4)2,(R,S)-(C5H5)Fe(2-Me(2)NCHMeC(5)H(3)) 3 and (S,R)-(C5H5)Fe(2-Me(2)NCHMeC(5)H(3)) 4] have been synthesized in high yield by treating the corresponding diselenides with elemental mercury. The compounds show excellent solubility in non-polar solvents. They were characterized by elemental analysis, H-1, C-13, Se-77 NMR, IR, Fourier-transform Raman and mass spectral techniques. The single-crystal structures of 1 and 4 were determined. Both are monomeric and the Hg atom is four-co-ordinate, being bound to a pair of chelating aminoselenolate ligands with both the six-membered rings having Se-Hg-N co-ordination adopting an envelope conformation. The bond configuration about Hg in 1 can be approximated to distorted tetrahedral, while in 4 it is more square planar with the two Se atoms being mutually trans and the Se-Hg-Se angle 168.6(2)degrees. Compounds 1 and 2 vaporize without decomposition at atmospheric pressure and decompose at higher temperatures to give HgSe while 3 decomposes to HgSe.