Sandwich type organic-inorganic hybrid of 3d-4f heterometallic containing germanotungstates [{Cu2(1,10-phen)2(μ-CH3COO)2}Ln(α-GeW11O39)2]11-: Syntheses, crystal structures, magnetic and photoluminescence properties

Alkali salts of organic-inorganic hybrid 3d-4f heterometallic containing derivatives of sandwich type germanotungstates: [{Cu-2(1,10-Phen)(2)(mu-CH3COO)(2)}Ln(alpha-GeW11O39)(2)](11-) [Ln = Pr-III (1a), Nd-III (2a), Sm-III (3a), Eu-III (4a), Gd-III (5a); 1,10-phen = 1.10-phenanthroline] have been prepared in the aqueous potassium acetate buffer (pH 4.7) solution. All these compounds were synthesized following by one pot reaction procedure under mild reaction conditions. All compounds were isolated as mixed alkali sodium/potassium salts from the solution and used for further structural characterization by single crystal XRD, powder-XRD, FT-IR, liquid UV/vis, solid state photoluminescence spectroscopy and thermo-gravimetric analysis. FT-IR spectra and powder-XRD pattern suggest that all compounds (1a-5a) are isomorphous. Further single crystal XRD analysis shows that all these compounds exhibit sandwich-type [Ln(alpha-GeW11O39)(2)](13-) structural feature in the polyoxoanions as the fundamental building block units, and the copper complexes coordinated with 1,10-phen and acetate ligands are coordinated to the. terminal oxygen of the polyanion. The compounds la, 3a and 4a show good photoluminescence properties at room temperature. The compound 5a shows weak ferromagnetic behavior. (C) 2016 Elsevier B.V. All rights reserved.