Chalcogenoether complexes of tantalum(V) sulfide trichloride – Synthesis, properties and structures

Abstract

The complexes [TaSCl3(L-L)] (L-L = MeSCH2CH2SMe, iPrSCH2CH2SiPr, PhSCH2CH2SPh, nBuSCH2CH2CH2SnBu, MeSCH2CH2CH2SMe, MeSeCH2CH2SeMe, nBuSeCH2CH2CH2SenBu) have been synthesised and isolated in good yield as powdered solids by the reaction of TaCl5 with the appropriate chalcogenoether in a 1:1 molar ratio in anhydrous CH2Cl2 solution at room temperature, followed by the addition of a CH2Cl2 solution containing one mol. equiv. of S(SiMe3)2. The isolated complexes were characterised by IR, 1H and 77Se{1H} NMR spectroscopy, as appropriate, and elemental analysis. Single crystal X-ray structure analyses for [TaSCl3(MeSCH2CH2SMe)], [TaSCl3(MeSeCH2CH2SeMe)], [TaSCl3(iPrSCH2CH2SiPr)] and [TaSCl3(nBuSCH2CH2CH2SnBu)] have been obtained. The data are compared with the previously described Nb(V) analogues. In contrast to the corresponding [NbSCl3(EnBu2)] (E = S, Se), attempts to isolate [TaSCl3(EnBu2)] were unsuccessful. Low pressure chemical vapour deposition (LPCVD) experiments using [TaSCl3(nBuSCH2CH2CH2SnBu)] did not lead to any deposition, whilst similar experiments using [TaSCl3(nBuSeCH2CH2CH2SenBu)] produced films containing only elemental Se, with no evidence for any deposition of tantalum sulfide or selenide films.