Structural Studies of Technetium Complexes. X. The Crystal-Structure of Tetraphenylarsonium Hexakis(Isothiocyanato)Technetate(IV)-Dichloromethane (1/1)

Abstract

The crystal structure of [AsPh₄]₂ [ Tc (NCS)₆].CH₂Cl₂ has been determined by single-crystal X-ray diffraction methods at 23 ± 1ºC . Crystals are tetragonal, space group I4/m, with a 11.523(5), c 22.43(2) Å, and Z 2. Diffraction data from two different crystals were analysed and in both cases disorder was present in the crystal lattices. Full-matrix least-squares refinement gave a final R value of 0.073 for 1188m independent reflections. The [TC(NCS)₆]^2- anion has an octahedral structure with the technetium(1V) atom situated on a site of 4/m symmetry. The Tc -N bond lengths are 2.00(1) and 2.01(1) Ǻ with N- Tc -N angles of exactly 90º. Two of the Tc -NCS groups are constrained by the crystal symmetry to be perfectly linear, while for the remaining four Tc -NCS groupings the Tc -N-C and N-C-S angles are 175.9(9)º and 175.3(10)º respectively.