Immobilization of Polyoxometalate in the Metal-Organic Framework rht-MOF-1: Towards a Highly Effective Heterogeneous Catalyst and Dye Scavenger

Abstract

A series of three remarkable complexes [PMo 12 O 40 ][Cu 6 O(TZI) 3 (H 2 O) 9 ] 4 ·OH·31H 2 O (H 3 TZI = 5-tetrazolylisophthalic acid; denoted as HLJU-1, HLJU = Heilongjiang University), [SiMo 12 O 40 ][Cu 6 O(TZI) 3 (H 2 O) 9 ] 4 ·32H 2 O (denoted as HLJU-2), and [PW 12 O 40 ][Cu 6 O(TZI) 3 (H 2 O) 6 ] 4 ·OH·31H 2 O (denoted as HLJU-3) have been isolated by using simple one-step solvothermal reaction of copper chloride, 5-tetrazolylisophthalic acid (H 3 TZI), and various Keggin-type polyoxometalates (POMs), respectively. Crystal analysis of HLJU 1-3 reveals that Keggin-type polyoxoanions have been fitted snuggly in the cages of rht-MOF-1 (MOF: metal-organic framework) with large cell volume in a range of 87968-88800 Å 3 and large pore volume of about 68%. HLJU 1-3 exhibit unique catalytic selectivity and reactivity in the oxidation of alkylbenzene with environmental benign oxidant under mild condition in aqueous phase as well as the uptake capacity towards organic pollutants in aqueous solution.