Two novel inorganic–organic hybrid materials constructed from two kinds of octamolybdate clusters and flexible tetradentate ligands

Abstract

Two novel hybrid materials based on two kinds of octamolybdate anions and metal–organic frameworks (MOFs), namely, [Ag₈(L¹)₄(α-Mo₈O₂₆)(β-Mo₈O₂₆)(H₂O)₃]·H₂O (1) and [Cu^I_3.1Cu^II_0.5(β-Mo₈O₂₆)_0.5(ζ-Mo₇^VIMo^VO₂₆)_0.5(L²)₂(H_0.8L²)_0.5] (2), where L¹ = 1,1′-(1,3-propanediyl)bis[2-(4-pyridyl)benzimidazole] and L² = 1,1′-(1,4-butanediyl)bis[2-(3-pyridyl)benzimidazole], have been successfully synthesized. Crystal structure analysis revealed that 1 is a three-dimensional (3D) framework constructed of silver(I)–organic sheets and two types of (Mo₈O₂₆)⁴⁻ isomers. Compound 2 is a rare 3D framework containing copper(I,II)–organic cages and 1D channels occupied by the (ζ-Mo₇^VIMo^VO₂₆)⁵⁻ and (β-Mo₈O₂₆)⁴⁻ anions. The two compounds were characterized by elemental analysis, IR spectroscopy, diffuse reflectivity spectroscopy, and photoluminescent spectroscopy. In addition, the photocatalytic behavior of 1 was investigated.