Baoxia Dong

Polyoxometalates with supporting phosphate ligand: synthesis and characterization of α-[SiW11O39M(H2PO4)]n−

A novel series of Keggin species with a covalently bonding support-ligand, formulated α-[SiW11O39M(H2PO4)]n− n(M = CoII, MnII, NiII or CrIII), have been synthesized and characterized by elemental analyses, IR, CV, NMR and X-ray powder diffraction measurements. The structure is reminiscent of an ancient Chinese three-legged wine vessel, and is a possible model for POM–nucleotide interaction. An interesting property is the different thermal behaviors for this series in comparison with those for corresponding 3d metal monosubstituted Keggin polyoxometalates. This can be attributed largely to the pendant surface ligand and H bonding interaction. Compared with α-PW11M, the orders of line broadening of 31P NMR signals are the same for the two series of complexes α-PW11M and α-SiW11M–PO4, but both contact and dipolar interactions might make a significant contribution to the chemical shift for phosphorus for the latter.

Hydrothermal syntheses and crystal structures of hybrid materials based on Keggin cluster modified by iron complexes

Three new organic-inorganic hybrid complexes based on the Keggin polyoxometalates (POMs) modified by transition metal iron and N-ligand organic moiety: [Fe(phen)3]2 (1) [Fe(phen)2(H2O)]2 u2009·u20092H2O (2) and [Fe(phen)3]2 u2009·u20090.5H2O (3) (phenu2009=u20091,10-phenanthroline) have been hydrothermally synthesized and structurally characterized. Crystal data for complex 1: C72H48Fe2M12N12O41PV, triclinic, , au2009=u200911.6618(2)u2009Å, bu2009=u200913.8523(2)u2009Å, cu2009=u200914.9168(2)u2009Å, αu2009=u2009105.87(3)°, βu2009=u200993.103(2)°, γu2009=u200996.609(2)°, Vu2009=u20092293.2(5)u2009Å3, Zu2009=u20091; for complex 2: C48H32Fe2PMo12N8O44, triclinic, , bu2009=u200913.357(3)u2009Å, cu2009=u200913.701(3)u2009Å, αu2009=u200969.09(3)°, βu2009=u200971.37(3)°, γu2009=u200978.21(3)°, Vu2009=u20091766.4(6)u2009Å3, Zu2009=u20091; for complex 3: C72H50Fe2Mo12N12O41Ge, triclinic, , bu2009=u200913.676(3)u2009Å, cu2009=u200914.627(3)u2009Å, αu2009=u2009105.05(3)°, βu2009=u2009109.64(3)°, γu2009=u200993.07(3) °, Vu2009=u20092185.6(7)u2009Å3, Zu2009=u20091. Other characterizations by element analysis, IR, XPS and TGA analysis are also described. Their electrochemical properties have been studied in the paper.

A novel inorganic-organic hybrid based on a Wells–Dawson polyanion containing two types of organic fragments

A new inorganic-organic hybrid, [Zn(phen)2(ppy)][{Zn(phen)2}{Zn(phen)2(H2O)}{P2W18O62}]u2009·u20092H2O (phenu2009=u20091,10′-phenanthroline, ppyu2009=u20092-(5-phenylpyridin-2-yl)pyridine) (1), by using pre-prepared Wells–Dawson salt α-K6P2W18O62u2009·u200915H2O as precursor, has been synthesized under hydrothermal conditions. Compound 1 was characterized by single-crystal X-ray diffraction, elemental analyses, IR spectrum and cyclic voltammetry. Yellow crystals crystallized in the monoclinic space group P2 (1)/c with au2009=u200916.2450(11)u2009Å, bu2009=u200917.0918(11)u2009Å, cu2009=u200943.640(3)u2009Å, βu2009=u200992.0060(10)°, Vu2009=u200912109.4(14)u2009Å3, Zu2009=u20094. The title compound represents a novel zero-dimensional structure based on bisupporting Wells–Dawson POM: one terminal oxygen atom located in the “belt” site and another located in the “cap” site of the same hemisphere of the polyanion are coordinated by Zn2+ cations. Compound 1 also contains the isolated secondary metal complex [Zn(phen)2(ppy)]2+ with two different organic ligands phen and ppy.