Generation of 19-Electron Adducts in Aqueous Solution Using the Water-Soluble (HOCH2)2PCH2CH2P(CH2OH)2Ligand

The utility of the water-soluble (HOCH2)2PCH2CH2P(CH2OH)2 ligand (dhmpe) in generating 19-electron complexes in aqueous solution was tested. In buffered aqueous solutions at pH 2, the ligand reacts with 17-electron radicals generated by photolysis of water-soluble [(CpCH2CH2NH3+)2Mo2(CO)6][NO3- ]2 to form 19-electron adducts. The formation of 19-electron adducts was established by disproportionation of [(CpCH2CH2NH3+)2Mo2(CO)6][NO3- ]2 and by the reduction of methyl viologen, both standard indicators of 19-electron adduct formation. The crystal structures of the (HOCH2)2PCH2CH2P(CH2OH)2 ligand and of one of its complexes, [Ni(dhmpe)2]Cl2, were determined.