Correlations between nuclear magnetic resonance spectra and crystal structure. III. A13C nuclear magnetic resonance study in the solid state of bis(xanthato) complexes of mercury(II); The crystal and molecular structure of bis(n-propyl-dithiocarbonato)mercury(II)

Abstract

The cross-polarization magic angle carbon-13 nmr spectra of a series of bis(xanthato) complexes of mercury(II) are reported; [Hg(S2COR)2] n R=Me, Et, n Pr and i Pr. The spectra correlate well with the known crystal structures of theR=Me, Et, and i Pr compounds and with that of theR= n Pr derivative for which a single-crystal X-ray diffraction study is also reported. The X-ray analysis of [Hg(S2CO n Pr)2] n shows that this compound adopts a two-dimensional structure comprised of connected 16-membered rings which arise as a result of bridgingn-propylxanthate ligands. The mercury atom lies on a crystallographic twofold axis of symmetry and exists in a distorted tetrahedral geometry with two unique Hg-S bond distances of 2.418(3) and 2.835(4) A. Unit-cell dimensions for [Hg(S2CO n Pr)2] n are:a=7.371(3),b=8.534(4),c=11.618(4) A andZ=2 for the orthorhombic space groupP21212. The structure was refined by a full-matrix least-squares procedure to finalR=0.047 andR w =0.044 for 899 reflections withI≥2.5σ(I). While the solid state nmr spectra provide information on molecular (and crystallographic) symmetry they do not provide sufficient detail to enable structure determination for the [Hg(S2COR)2] compounds.