Interconverting edge-sharing and face-sharing bioctahedral dinuclear tungsten(III) phosphine complexes. Preparations, properties, and structures of W2Cl6L4, where L = PMe3, PEt3, and P(n-Bu)3, W2Cl6L3, where L = PEt3 and P(n-Bu)3, and [HPEt3]+[W2Cl7(PEt3)2]-

In tetrahydrofuran solution the sodium salt of the [W 2 Cl 7 (THF) 2 ] - anion and the tertiary phosphines PR 3 (≥4 equiv) react at room temperature to give red crystalline compounds W 2 Cl 6 (PR 3 ) 4 , where R=Me, Et, and n-Bu. The compounds where R=Me and Et have been characterized by single-crystal X-ray crystallography and were shown to contain an edge-shared bioctahedral (ESBO) geometry cl 2 P 2 W(μ-cl) 2 WCl 2 P 2 with W-W=ca. 2.72 A.