Thioxanthate complexes of {Nb2S4}4+

Abstract The new alkylthioxanthate complexes [Nb 2 S 4 (S 2 CSR) 4 ] (R = CH 3 ( 1 ), C 2 H 5 ( 2 ), i -C 3 H 7 ( 3 ) and n -C 4 H 9 ( 4 )) were obtained by alkylation of [Nb 2 S 4 (CS 3 ) 4 ] 4− with the corresponding alkyl iodides ( 1 – 3 ) or bromide ( 4 ) in moderate yields. For [Nb 2 S 4 (S 2 CSC 2 H 5 ) 4 ] ( 2 ) and [Nb 2 S 4 (S 2 CS n C 4 H 9 ) 4 ] ( 4 ), crystal structures have been determined. The structure of 2 is a racemic mixture of ΛΛ and ΔΔ isomers, while [Nb 2 S 4 (S 2 CS n C 4 H 9 ) 4 ] ( 4 ) crystallizes as the ΛΔ isomer. The Nb–Nb distances in 2 and 4 are 2.87–2.88 A. Thermal decomposition leads to amorphous NbS 2 .