An unprecedented extended architecture constructed from a 2-D interpenetrating cationic coordination framework templated by SiW12O404– anion

A novel inorganic-organic hybrid compound based on polyoxometalates (POMs) and organic ligand formulated as [Cu2(bpp)4(H2O)2](SiW12O40)∼6H2O (1) [bpp=1,3-bis(4-pyridyl)propane], was hydrothermally synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction analysis, IR, TG, and cyclic voltammetry. Crystal data for 1: Orthorhombic, Pbcn, a=23.0085(19) Å, b=14.6379(12) Å, c=23.6226(19) Å, V=7956.0(11) Å3, Z=4, Dc=3.315 g cm–3, and R(final)=0.0826. X-ray diffraction study reveals that compound 1 was the first interpenetrating network of 2-D metal–organic cationic coordination framework [Cu2(bpp)4(H2O)2]n4n+, in which Keggin-type anions SiW12O404– has been used as a non-coordinating anionic template. The electrochemical property of 1-bulk modified carbon paste electrode (1-CPE) has been studied, and the results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite in 1 M H2SO4 aqueous solution.

Compound [Cu2(bpp)4(H2O)2](SiW12O40)∼6H2O (1) represents the first 2-D interpenetrating cationic metal–organic frameworks (MOFs) templated by Keggin-type anions. These MOF layers are stacked together along the crystallographic c axis exactly to construct large cubic-like channels (with dimensions of 12.3×13.6 Å) occupied by SiW12O404– clusters.Figure optionsDownload as PowerPoint slide