Adaptive Coordination Behavior of Bisphosphanylphosphanido-Ligands Toward Group 2, 11 and 12 Metal Ions.

A series of alkaline earth metal complexes (Mg-Ba) with the anionic ferrocenylene-bridged bisphosphanylphosphanide ligand [Fe(CHPCH)P] has been prepared by metalation of the corresponding bisphosphanylhydrophosphane (Fe(CHPCH)PH). The resulting complexes have been characterized by multinuclear NMR spectroscopy and SC-XRD. Furthermore, the closely related zinc phosphanide, and rare, mononuclear coinage metal phosphanides were synthesized and investigated for comparison. The range of coordination modes observed for the phosphanide ligand included mono-, bi-, and tridentate modi and their respective combinations, whereas no μ-bridging of the phosphanide center has been observed. The value of the J coupling constant was found to be a good probe to track the coordination motif consistent with the situation in solid state.