Two Novel Catalysts Constituted by Transition Metal-Oxide-Based Cluster Cation Frameworks with Big Ellipse Cavities Accommodated with {PMo12O40} Cluster Anions for Multifunctional Catalytic Properties

Abstract

Two novel hybrid compounds, [{Mo(NO3)2(2,2′-bpy)}0.5{Mo6O17(2,2′-bpy)6}][PMo12O40] (1); [{Mn(2,2′-bpy)2}0.5{Mo6O17(2,2′-bpy)6}][PMo12O40] (2) (bpy = 2,2′-bpyridine), have been synthesized under mild hydrothermal conditions and structurally characterized by physico-chemical and series of spectroscopic methods. Two rare compounds which are basically isostructural with similar cell parameters are composed of transition metal-oxide-based cluster cations (TMOC) and classical Keggin type {PMo12O40} anions. Both [{Mo(NO3)2(2,2′-bpy)}0.5{Mo6O17(2,2′-bpy)6}]n and [{Mn(2,2′-bpy)2}0.5{Mo6O17(2,2′-bpy)6}]n cluster cation fragments possess opened railway molybdenum-oxide-based infinite cation chains. Then through O⋯O bond interactions, the adjacent railway chains are linked together with inverse symmetry mode to generate two kinds of interesting 2D supramolecular positive layers accommodated with big ellipse {PMo12O40} anions. By H-bonding interactions, the alternative accumulations between layers and layers give rise to 3D supramolecular channel frameworks, and the {PMo12O40} anions from different layers each other also generate graphene-like negative inorganic sheets. The electrochemical behaviors and electrocatalytic activities of both compounds have been explored. The photocatalytic activities of compounds 1 and 2 for decomposition of rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) under UV irradiation also have been investigated. The catalytic performances for the tertbutyl hydroperoxide (TBHP) oxidation of styrene also were carried out. The results show that compounds 1 and 2 exhibit multifunctional catalytic performances.