Structural systematics of tellurium(II) bis(O-alkyldithiocarbonate) and tellurium(II) bis(N,N-dialkyldithiocarbamate) compounds

Abstract

Abstract The crystal and molecular structures of three compounds, Te(S2COR)2, R = iBu and CH2Ph, and Te(S2CNCy2)2 have been determined at 200 K. The red crystals of [Te(S2COiBu)2] are monoclinic, space group P21/c with unit cell dimensions a = 15.535(10) Å, b = 10.402(4) Å, c = 10.832(4) Å, β = 109.43(5)°, Z = 4 and D x = 1.714 Mg m−3. The red crystals of [Te(S2COCH2Ph)2] are monoclinic, space group P21/n with unit cell dimensions a = 8.28(1) Å, b = 5.66(1) Å, c = 38.19(1) Å, β = 91.7(1)°, Z = 4 and D x = 1.834 Mg m−3. Crystals of red [Te(S2CNCy2)2] are monoclinic, space group P21/n with unit cell dimensions a = 9.417(3) Å, b = 27.11(1) Å, c = 11.745(3) Å, β = 102.10(2)°, Z = 4 and D x = 1.451 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.035 using 2741 reflections for [Te(S2COiBu)2]; to R = 0.037 using 3062 reflections for(Te(S2COCH2Ph)2]; and to final R = 0.054 for 2722 reflections for [Te(S2CNCy2)2]. The tellurium atom in each of the structures exists in a trapezoidal planar geometry defined by four sulfur atoms derived from two asymmetrically coordinating 1,1-dithiolate ligands. Attempts to correlate the magnitude of the Te–S distances with the nature of R in the respective series of Te(S2COR)2 and Te(S2CNR2)2 compounds failed, nor was it possible to correlate Te–S with intermolecular Te ⋯ S interactions. Crystal packing forces are suggested to play a significant role in influencing the molecular parameters about the tellurium atoms in these systems.