Tetrathiovanadate(V) and tetrathiorhenate(VII): structures and reactions, including characterization of the VFe2S4 core unit

Abstract

The structural and derivative chemistry of (VS/sub 4/)/sup 3 -/ and (ReS/sub 4/)/sup -/ has been investigated. (NH/sub 4/)/sub 3/(VS/sub 4/) crystallizes in orthorhombic space group Pnma with a = 9.432 (2) A, b = 10.825 (2) A, c = 9.309 (2) A, and Z = 4. (n-Bu/sub 4/N)(ReS/sub 4/) occurs in orthorhombic space group Pcnn with a = 11.355 (2) A, b = 11.343 (2) A, c = 18.566 (2) A, and Z = 4. Both ions are slightly distorted tetrahedra with the mean bond lengths V-S = 2.154 (16) A and Re-S = 2.123 (5) A. The /sup 187/Re resonance of (ReS/sub 4/)/sup -/ occurs at 2586 ppm downfield of (ReO/sub 4/)/sup -/ in acetonitrile at 297 K. The reaction system (NH/sub 4/)/sub 3/(VS/sub 4/)/FeCl/sub 2/ in acetonitrile affords the trinuclear cluster (VFe/sub 2/S/sub 4/Cl/sub 4/)/sup 3 -/ (1) in good yield. (Me/sub 4/N)/sub 3/(VFe/sub 2/S/sub 4/Cl/sub 4/).DMF crystallizes in monoclinic space group P2/sub 1//c with a = 16.058 (3) A, b = 11.371 (2) A, c = 19.856 (4) A, ..beta.. = 110.20 (1)/sup 0/, and Z = 4. The anion contains a new structural unit, the nearly linear (Fe(..mu..-S)/sub 2/V(..mu..-S)/sub 2/Fe)/sup +/ core (Fe-V-Fe = 172.9more » (1)/sup 0/), and is formed from three edge-shared tetrahedra. The overall symmetry of (VFe/sub 2/S/sub 4/Cl/sub 4/)/sup 3 -/ closely approaches D/sub 2d/; the cluster is isostructural with (MFe/sub 2/S/sub 4/Cl/sub 4/)/sup 2 -/ (M = Mo, W). 49 references, 7 figures, 6 tables.« less