The crystal and molecular structures of [Te(S2COR)2],R = nPr and CH2CH2CMe3

The crystal and molecular structures of bis(n-propyldithiocarbonato)tellurium (II), [Te(S 2 COnPr) 2 ] (1), C 8 H 14 O 2 S 4 Te, and bis(3,3-dimethylbutyldithiocarbonato)tellurium(II), [Te(S 2 COCH 2 CH 2 CMe 3 ) 2 ] (2), C 14 H 26 O 2 S 4 Te, have been determined at room temperature. The red crystals of 1 are monoclinic, space group P2 1 with unit cell dimensions a = 10.501(6) A, b = 5.973(3) A, c = 12.055(1) A, β = 102.39(2)°, Z = 2 and D x = 1.790 Mg m -3 . The red crystals of 2 are also monoclinic, space group P2 1 /c with unit cell dimensions a = 16.744(6) A, b = 6.098(4) A, c = 21.334(3) A, β = 104.89(2)°, Z = 4 and D x = 1.521 Mg m -3 . The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.046 using 1314 reflections for 1 and to final R = 0.061 using 1194 reflections for 2. The molecular structures are similar and each feature two asymmetrically coordinating xanthate ligands that define a trapezoidal planar coordination geometry about the tellurium(II) center; the lone pairs of electrons are thought to lie over the weaker Te-S interactions. Each of the crystal structures is stabilised by supramolecular Te...S interactions.