Main Group Metal Halide Complexes with Sterically Hindered Thioureas XII. Crystallographic Studies of Lead(II) and Cadmium(II) Thiocyanate Complexes with 1,3-Dimethyl-2(3H)-imidazolethione
Pb(NCS)2(dmit)2 (I) was previously reported (dmit = 1,3-dimethyl-2(3H)-imidazolethione). New Cd(NCS)2(dmit)2 (II) was synthesized and characterized. Single crystal x-ray structural studies were completed for both complexes. I and II crystd. as monoclinic, space group C2/c, Z = 4, R = 0.030 and 0.031, resp. Both complexes are isostructural polymers comprised of zigzag chains of MS4N2 distorted octahedra sharing common edges through almost perfectly linear bridging SCN groups cis to each other relative to the central metal atom. Thiourea ligands are trans to each other. Comparative bond distances show the formulation of these complexes to be more accurately stated as M(NCS)2(dmit)2. There is no clear evidence for the lone pair of electrons through systematic distortions in the Pb structure although there are greater obsd. deviations from 90° in the local site symmetry about Pb than about Cd.