Solvent-dependent conformational polymorphism in the crystal structure of mercuric bromide adduct of 1,1′-bis(diphenylphosphino)ferrocene

Two polymorphs of dinuclear mercury–iron complexes, [HgBr2(dppf)] (1) where dppf is 1,1′-bis(diphenylphosphino)ferrocene, are prepared and crystal structures are determined by X-ray crystallography. The reaction of mercury(II) bromide with dppf in methanol–dichloromethane led to orange block polymorph. After crystallization of this complex in DMSO, a red needle polymorph was obtained.