Inorganic–organic hybrid framework materials: Synthesis and characterization of [{Co(H 2O)(L)} 2V 4O 12] (L = pyridine, 4-methlypyridine)

Abstract

Inorganic–organic hybrid materials – [{Co(H 2O)(py)} 2V 4O 12] ( 1) and [{Co(H 2O)(pic)} 2V 4O 12] (pic = 4-methylpyridine) ( 2) have been synthesized and characterized by FT-IR spectroscopy, thermogravimetric analysis, elemental analysis, manganometric titration, temperature dependent magnetic susceptibility measurement, bond valence sum calculations, and single crystal X-ray diffraction analyses. Crystals of 1– 2 have very similar structures. The two-dimensional framework structures consist of bimetallic oxide layers, composed of {VO 4} tetrahedra and {CoO 5N} octahedra bridged by oxygen atoms, with pyridine rings projecting outward on both sides of the layers. The 12 membered metallocycles – {Co 2V 4O 6} – in the layers generate cavities. The hydrophobic pyridine rings engage in π-stacking with the aromatic rings from adjacent layers. Crystal data for 1; C 10H 14Co 2N 2O 14V 4, triclinic space group P 1 ¯ , a = 7.7952(8), b = 10.9620(11), c = 12.8778(13) Ǻ, α = 65.940(2), β = 89.318(2), γ = 88.762(2), Z = 2; crystal data for 2: C 12H 18N 2Co 2O 14V 4, monoclinic space group P2 1/ m, a = 10.9361(15), b = 7.8201(11), c = 14.0224(19) Ǻ, α = 90.0, β = 112.314(2), γ = 90.0, Z = 2.