Two 3D Two-Fold Interpenetrated Dia-Like Polyoxometalate-Based Metal–Organic Frameworks: Synthesis and Sulfide Selective Oxidation Activity

Abstract

Two new three-dimensional (3D) polyoxometalate-based metal− organic frameworks (POMOFs), [M 2 (btap) 4 (H 2 O) 4 (HPMo 10 VI Mo 2 V O 40 )] (M = Co (1) and Cd ( 2); btap = 3, 5-bis(1′, 2′, 4′-triazol-1′-yl)pyridine), have been synthesized under mild hydrothermal conditions and characterized in detail. Single-crystal X-ray diffraction (SXRD) analysis indicates that 1 and 2 are isostructural. In complexes 1 and 2, the metal ion is coordinated with the ligand to form two different left and right helical one-dimensional chains, which are alternately connected in a twisted form to build a two-fold interpenetrated threedimensional structure, and the polyoxometalate is encapsulated into in the pores generated by the interpenetrating structure. It is noteworthy that 1 and 2, as recyclable catalysts, possess favorable heterogeneous catalytic activity and excellent sulfoxide selectivity in sulfide oxidation reactions, with H 2 O 2 as an oxidant. By reason of the high dispersion of polyoxometalate with good intrinsic activity in the skeleton structure, the title complex has high activity. In addition, no obvious decrease of sulfoxide yield is observed after at least five cycles. These results indicate the excellent catalytic activity and sustainability of 1 and 2.

Four Chromic Compounds Constructed from Keggin Polyoxometalates and Viologens with Applications in Ultraviolet, Metal Ion Detection, and Ink-Free Printing

“…In compound 1 , it was detected that C 1s, O 1s, N 1s, P 2p, Mo 3d, and Cu 2p coexist (Figure a). The Mo 3d of 1 has four overlapping peaks (Figure S7), which are located at 231.92 eV, 232.90 eV, 235.17, and 236.05 eV, respectively, belonging to the mixed peaks of Mo V and Mo VI . , In compound 3 , C 1s, O 1s, N 1s, Si 2p, and Mo 3d were detected to coexist (Figure S13a).…”

Assembly of Lanthanide-Containing 3D [MnMo9O32]6–-Based Metal–Organic Frameworks and Oxidative Desulfurization Performance

“…The N-heterocyclic organic ligand pyridine-2,6-dicarboxylate, which possesses multiple coordination sites and versatile coordination behaviors and bears a 120° angle between the pyridine ring and bilateral carboxylate groups, has been widely used to construct Ln-containing MOFs; − hence, it could be a good choice in the assembly of Ln-containing POMOFs. Furthermore, to our knowledge, a number of POMOFs exhibit good catalytic activity in many organic reactions, , like oxidative desulfurization (ODS), which has been regarded as one of the most promising technologies for deep desulfurization due to its mild reaction conditions and environmentally friendliness. − Notably, Waugh-type [MnMo 9 O 32 ] 6– -based compounds have been observed to show good catalytic performance for ODS …”