Chiral {Ni₆PW₉} Cluster–Organic Framework: Synthesis, Structure, and Properties

Abstract

A chiral three-dimensional polyoxometalate cluster–organic framework (POMCOF) H3[(btc)­Ni6(μ3-OH)3(H2O)5(B-α-PW9O34)]·17H2O (1, btc = 1,2,4-benzenetricarboxylate) has been made under hydrothermal conditions in the absence of amine or chiral starting reagents. 1 shows high stability in CH3CN/DMF (1:3), acidic, and basic solutions with the pH ranging from 2 to 12 for 5 days. The UV–vis reflectance spectra and Mott–Schottky measurements reveal that 1 could be a suitable catalyst for photocatalysis. Visible-light-driven H2 evolution studies have demonstrated that 1 is an ecofriendly, efficient, and recyclable catalyst with a H2 evolution rate of 1058.24 μmol h–1g–1. Nonlinear optical (NLO) measurement reveals that 1 exhibits a second-harmonic generation (SHG) response of about 1.4 times that of KH2PO4 (KDP), indicating that 1 is a potential NLO material as well.

40Ni-Added Poly(polyoxometalate) Assembled by {Ni6GeW9} and {Ni8(GeW9)2} Units: Structure, Magnetic, and Heterogeneous Catalysis Properties

“…The synergistic effect of POM and transition metals can provide potential opportunity for photocatalysis. − ,− Therefore, we investigated the photocatalytic hydrogen production of 1 in detail. As shown in Figure , under white LED irradiation, the production of H 2 increased continuously with time, but the production rate of H 2 slowed down at prolonged reaction time.…”

“…For instance, high-nuclearity Ni 20 -, Ni 22 -, Ni 24 -, and Ni 40 -added POMs have exhibited interesting molecular magnetism with overall ferromagnetic interactions. In addition, the NiAPs also showed broad catalytic applications, including Knoevenagel condensation, oxidation of sulfides, visible-light-driven water oxidation, photoreduction of CO 2 , visible-light-driven H 2 evolution, − etc. Given the fact that Ni centers are the active sites of natural [NiFe] hydrogenases for efficient hydrogen uptake and proton reduction, comprehensive studies of NiAPs as catalysts for photocatalytic H 2 production remain a particularly interesting research area.…”

State-of-the-art advances in the syntheses, structures, and applications of polyoxometalate-based metal–organic frameworks

“…14a) is extremely promising for the designed synthesis of uncommon POM-MOFs via substituting active sites with different organic ligands. 100,101 In the aspect, Yang and coworkers isolated a series of fascinating 1-D, 2-D and 3-D POM-MOFs by combing in-situ-generated {Ni6PW9(H2O)6} BB with rigid carboxylate ligands. 102 The utilization of V-shaped 1,3-benzenedicarboxylic acid (1,3-H2bdc) and thiophenedicarboxylic acid (H2tda) affords the first 1-D zigzag chain built by {Ni6PW9(H2O)n} BBs and 1,3-bdc 2-/Htdalinkers, in which {{Ni6PW9(OH)3(H2O)2(enMe)3} (enMe = 1,2-diaminopropane) and {Ni6PW9(OH)3(H2O)(en)4}…”

Construction of Hexameric Ru-Substitution POMs to Improve Photocatalytic H2 Evolution

“…Note that the [Ir(ppy) 2 (dtbbpy)][PF 6 ] catalytic system produced substantially more H 2 than the [Ru(bpy) 3 ] 2+ catalytic system did (Figure S20), demonstrating the critical effect of the photosensitizer's light absorption ability on the catalytic activity. 63 Moreover, when {As 6 W 65 } was used as the catalyst, the H 2 evolution rate was only 533.33 μmol g −1 h −1 , indicating a synergistic effect between the central metal− oxygen cluster and {As 6 W 65 } (Figure S21). The distinction in the photocatalytic H 2 evolution activity of 1 and 2 can be reasonably explained by the difference in their molecular structures.…”