Sandwich type organic-inorganic hybrid of silicotungstates [{Cu-2(1,10-phen)(2)(mu-CH3COO)(2)}Ln(alpha-SiW11O39)(2)](11-) {Ln = Pr-III(1a), Nd-III(2a), Sm-III(3a), Eu-III(4a), Gd-III(5a) and Dy-III(6a)}: Syntheses, crystal structures, photoluminescence and magnetic properties

摘要

Isomorphous sandwich type silicotungstates: Alkali salts of [{Cu-2(1,10-phen)(2)(mu-CH3COO)(2)}Ln(alpha-SiW11O39)(2)](11-) {Ln = Pr-III(1a), Nd-III(2a), Sm-III(3a), Eu-III(4a), Gd-III(5a) and Dy-III(6a)} (where 1,10-phen = 1,10-phenanthroline) were isolated using a single step reaction of Na-10[A-alpha-SiW9O34]center dot 16H(2)O with Cu(NO3)(2)center dot 5H(2)O, Ln(NO3)(3)center dot nH(2)O and 1,10-phen in potassium acetate buffer at pH-4.5. All these compounds were isolated as alkali salts and characterized by single crystal X-ray diffraction and other analytical techniques including FT-IR, liquid UV/vis, thermogravimetric analysis and magnetic studies on Gd-III(5a). The single crystal X-ray diffraction and FT-IR studies suggest that the compounds are isostructural and crystallize in triclinic crystal system with space group P-1. The single crystal structural analysis reveals that it consists of organic-inorganic hybrid polymeric chain in which copper complex with 1,10-phen with a paddle wheel like shape and also forms network with pi-pi stacking. Photoluminescence properties of Pr(1a), Eu(4a) and Dy(6a) were investigated at room temperature. Magnetic studies show that the compound Gd(5a) exhibits superparamagneticbehavior in the presence of applied magnetic field. (C) 2016 Elsevier B.V. All rights reserved.