The synthesis of technetium(V) complexes containing sterically bulky thiolate ligands. The molecular structure of tetrabutylammonium oxotetrakis(2,4,6-trimethylbenzenethiolato)technetate(V)

Abstract

The reactions between [TcOCl 4] − and the sterically bulky thiols ArSH (Ar = 2,4,6-Me 3C 6H 2, 2,4,6- Pr i 3C 6H 2 and 2,6-Ph 2C 6H 3) in methanol afford complexes of formula [TcO(SAr) 4] − which may be isolated as salts with bulky organic cations. The molecular structure of [Bu n 4N][TcO(2,4,6-Me 3C 6H 2S) 4] was determined by X-ray diffraction methods. The Tc(V) centre was found to adopt the expected square pyramidal geometry in which an oxo group occupies the apical site and the four thiolate sulphurs the basal sites. The TcO distance is 1.659(11) Å and the average TcS distance 2.38(2) Å. The average cis STcS, trans STcS and OTcS angles are respectively 82.7(6)°, 138.4(3)° and 110.8(4)°.