Dirhodium-Based Supramolecular Framework Catalyst for Visible-Light-Driven Hydrogen Evolution

Abstract

The direct conversion of solar energy to clean fuels as alternatives to fossil fuels is an important approach for addressing the global energy shortage and environmental problems. Here, we introduce a new dirhodium-complex-based framework assembly as a heterogeneous molecule-based photocatalyst for hydrogen evolution using visible light. Two dirhodium complexes bearing visible-light-harvesting BODIPY (boron dipyrromethene, BDP) moieties were newly designed and synthesized. The obtained complexes were self-assembled to framework structures (supramolecular framework catalysts), which are stabilized intermolecular noncovalent interactions. These frameworks retained excellent visible-light-harvesting properties of BDP moieties. Investigation of the catalytic performance of the supramolecular framework catalysts revealed that the supramolecular framework catalyst with heavy atoms at BDP moieties exhibited excellent performance in the formation of hydrogen with a reaction rate of 275.8 μmol g–1 h–1 under irradiation of visible light, whereas the supramolecular framework catalyst without heavy atoms at BDP moieties was inactive. Moreover, the system has the additional benefits of high durability (up to 96 h), reusability, and facile removal from the reaction mixture. We also disclosed the effect of heavy atoms at BDP moieties on the catalytic activity and proposed a reaction mechanism.

8-[4-(2-Hydroxypropane-2-yl)phenyl]-1,3,4,4,5,7-hexamethyl-4-boron-3a,4a-diaza-S-indacene

“…The problems may arise from dehydration of tertiary alcohol with the formation of carbocation, which also might be active in reactions with pyrrole. At the next step, we synthesized BODIPY 4 according to the literature procedure [10]. The reaction of BODIPY 4 with excess of MeMgI resulted in the exchange of fluorines to methyl groups and the transformation of CO2Me to 2-hydroxyprop-2-yl fragments (Scheme 2).…”

“…The analysis of isolated fractions has not revealed any useful products. BODIPY 3 was prepared according to published procedure [10]. To a solution of 0.0320 g (0.084 mmol) of BODIPY 4 in 20 mL of dry diethyl ether, 0.28 mL (0.84 mmol) of 3M solution of MeMgI in diethyl ether was added under argon atmosphere.…”

Computational analysis of metal–metal bonded dimetal tetrabenzoate redox potentials in the context of ammonia oxidation electrocatalysis

“…[58][59][60][61][62][63][64][65] Rh 2 benzoate-derived complexes have been examined for their host-guest, [66][67][68][69][70][71][72][73][74] structural, [75][76][77][78][79][80][81][82][83] light absorbing, [84][85][86] catalytic, 87,88 kinetic, 89 and hydrogen evolution properties. 90 Dirhenium tetrabenzoate is known in the Re 2…”

X-H Bond Insertion Promoted by Heterogeneous Dirhodium Metal–Organic Cage with Alkynes as Safe Carbene Precursors

“…Rhodium(II) complexes, especially the chiral rhodium(II) carboxylic acids, are indispensable catalysts in many processes for the production of pharmaceuticals and fine chemicals, including cyclopropanations, X-H insertions, ylide transformations, and so on [ 6 , 7 , 8 ]. Recently, dirhodium(II) complexes even found use in photocatalysis for hydrogen evolution and carbon dioxide reduction [ 9 , 10 , 11 ]. Despite high activity and selectivity, the unavoidable high cost, the difficulty in recovering and recycling, and the metal contamination of pharmaceuticals became the main factors that limited the application of dirhodium catalysts in the chemical industry.…”