Complex containing the bridging formazanido(3–) ligand. Synthesis and X-ray crystal structure of [{WBr(dppe)2}2{µ-CH(N2)2}]+[Cr(NH3)2(NCS)4]–.1/3CH2Cl2

Abstract

The reaction between [WBr(dppe)₂N₂H₂]⁺Br^– and CHFBr₂, in the presence of [Ph₂I]⁺Br^– and aqueous base, yields a cationic, dinuclear complex [{WBr(dppe)₂}₂{µ-CH(N₂)₂}]⁺, which has been isolated as its bromide, hexafluorophosphate, and Reineckate salts; a single crystal X-ray study of the latter confirms that the cation contains a formazanido (3–) ligand [NNCHNN]^3–, bridging two tungsten atoms in a fully conjugated, 7-atom chain.