title: Synthesis and characterization of copper-, zinc-, manganese-, and cobalt-substituted dimeric heteropolyanions, [(alpha-XW9O33)2M3(H2O)3](n-) (n = 12, X =As(III), Sb(III), M = Cu(2+), Zn(2+); n = 10, X = Se(IV), Te(IV), M = Cu(2+) and [(alpha-AsW9O33)2WO(H2O)M2(H2O)2](10-) (M = Zn(2+), Mn(2+), Co(2+).
abstract: Interaction of the lacunary [alpha-XW9O33](9-) (X = As(III), Sb(III)) with Cu(2+) and Zn(2+) ions in neutral, aqueous medium leads to the formation of dimeric polyoxoanions, [(alpha-XW9O33)2M3(H2O)3](12-) (M = Cu(2+), Zn(2+); X = As(III), Sb(III)), in high yield. The selenium and tellurium analogues of the copper-containing heteropolyanions are also reported: [(alpha-XW9O33)2Cu3(H2O)3](10-) (X = Se(IV), Te(IV)). The polyanions consist of two [alpha-XW9O33] units joined by three equivalent Cu(2+) (X = As, Sb, Se, Te) or Zn(2+) (X = As, Sb) ions. All copper and zinc ions have one terminal water molecule resulting in square-pyramidal coordination geometry. Therefore, the title anions have idealized D3h symmetry. The space between the three transition metal ions is occupied by three sodium ions (M = Cu(2+), Zn(2+); X = As(III), Sb(III)) or potassium ions (M = Cu(2+); X = Se(IV), Te(IV)) leading to a central belt of six metal atoms alternating in position. Reaction of [alpha-AsW9O33](9-) with Zn(2+), Co(2+), and Mn(2+) ions in acidic medium (pH = 4-5) results in the same structural type but with a lower degree of transition-metal substitution, [(alpha-AsW9O33)2WO(H2O)M2(H2O)2](10-) (M = Zn(2+), Co(2+), Mn(2+)). All nine compounds are characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. The solution properties of [(alpha-XW9O33)2Zn3(H2O)3](12-) (X = As(III), Sb(III)) were also studied by 183W-NMR spectroscopy.
authors.affiliation: Department of Chemistry, American University of Beirut, P.O. Box 11-0236, Riad El Solh Beirut 1107 2020, Lebanon. ulrich.kortz@aub.edu.lb
authors.forename: U
authors.initials: U
authors.lastname: Kortz
authors.forename: N K
authors.initials: NK
authors.lastname: Al-Kassem
authors.forename: M G
authors.initials: MG
authors.lastname: Savelieff
authors.forename: N A
authors.initials: NA
authors.lastname: Al Kadi
authors.forename: M
authors.initials: M
authors.lastname: Sadakane
mesh_terms: D000838:Anions; D003035:Cobalt / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008345:Manganese / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D012492:Salts / Q000138:chemical synthesis* / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
chemical_list: D000838:Anions; D007202:Indicators and Reagents; D012492:Salts; D003035:Cobalt; D008345:Manganese; D003300:Copper; D015032:Zinc