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

Abstract The complexes [TaSCl 3 (L-L)] (L-L = MeSCH 2 CH 2 SMe, i PrSCH 2 CH 2 S i Pr, PhSCH 2 CH 2 SPh, n BuSCH 2 CH 2 CH 2 S n Bu, MeSCH 2 CH 2 CH 2 SMe, MeSeCH 2 CH 2 SeMe, n BuSeCH 2 CH 2 CH 2 Se n Bu) have been synthesised and isolated in good yield as powdered solids by the reaction of TaCl 5 with the appropriate chalcogenoether in a 1:1 molar ratio in anhydrous CH 2 Cl 2 solution at room temperature, followed by the addition of a CH 2 Cl 2 solution containing one mol. equiv. of S(SiMe 3 ) 2 . The isolated complexes were characterised by IR, 1 H and 77 Se{ 1 H} NMR spectroscopy, as appropriate, and elemental analysis. Single crystal X-ray structure analyses for [TaSCl 3 (MeSCH 2 CH 2 SMe)], [TaSCl 3 (MeSeCH 2 CH 2 SeMe)], [TaSCl 3 ( i PrSCH 2 CH 2 S i Pr)] and [TaSCl 3 ( n BuSCH 2 CH 2 CH 2 S n Bu)] have been obtained. The data are compared with the previously described Nb(V) analogues. In contrast to the corresponding [NbSCl 3 (E n Bu 2 )] (E = S, Se), attempts to isolate [TaSCl 3 (E n Bu 2 )] were unsuccessful. Low pressure chemical vapour deposition (LPCVD) experiments using [TaSCl 3 ( n BuSCH 2 CH 2 CH 2 S n Bu)] did not lead to any deposition, whilst similar experiments using [TaSCl 3 ( n BuSeCH 2 CH 2 CH 2 Se n Bu)] produced films containing only elemental Se, with no evidence for any deposition of tantalum sulfide or selenide films.