Synthesis and structure of bis(diethyldithiocarbamato)nitridotechnetium(V): a technetium–nitrogen triple bond

Abstract

The title compound [Tc(S₂CNEt₂)₂N] has been prepared by the reduction of [NH₄][TcO₄] with hydrazine followed by reaction with Na[S₂CNEt₂]. The crystal structure of [Tc(S₂CNEt₂)₂N] has been determined by single-crystal X-ray diffraction methods at 17 °C. Crystals are monoclinic, space group P2₁/c, with a= 14.823(1), b= 9.159(1), c= 12.865(1)Å, β= 107.98(1)°, and Z= 4. Diffractometry has provided significant Bragg intensities for 2 152 independent reflections and the structure has been refined by full-matrix least-squares methods to R 0.042. The compound, which is isostructural with the rhenium analogue, consists of discrete [Tc(S₂CNEt₂)₂N] molecules, each containing a terminal N^3– group. The technetium atom has a distorted square-pyramidal environment with the nitrogen atom in the apical position and four sulphur atoms forming the base. The TcN bond, which has not been observed before, has a length of 1.604(6)Å, and the Tc–S bond distances range between 2.392(2) and 2.405(2)Å.