An Anthracene-Based Metal-Organic Framework for Selective Photo-Reduction of Carbon Dioxide to Formic Acid Coupled with Water Oxidation

A Zr-based metal-organic framework has been synthesized and employed as a catalyst for photochemical carbon dioxide reduction coupled with water oxidation. The catalyst shows significant carbon dioxide reduction property with concomitant water oxidation. The catalyst has broad visible light as well as UV light absorption property, which is further confirmed from electronic absorption spectroscopy. Formic acid was the only reduced product from carbon dioxide with a turn-over frequency (TOF) of 0.69 h⁻¹ in addition to oxygen, which was produced with a TOF of 0.54 h⁻¹. No external photosensitizer is used and the ligand itself acts as the light harvester. The efficient and selective photochemical carbon dioxide reduction to formic acid with concomitant water oxidation using Zr-based MOF as catalyst is thus demonstrated here.     

1H and 13C NMR Determination of the Enantiomeric Purity of Substituted 4-Amino-3- (thien-2-Yl)-Butyric Acids and 4-Amino-3-(Benzo[b]Furan-2-yl)-Butyric Acids,Ligands of the GabaB Receptor.

The enantiomeric composition and absolute configuration of 4-Amino-3-(benzo[b]furan-2-yl)-Butanoic Acids and of 4-Amino-3-(thien-2-yl)-Butanoic Acids 1 may be accurately determined by ¹H and ¹³C nuclear magnetic resonance analysis of the corresponding derivatives 3 prepared by reaction with chiral reagents. Correlation with HPLC is signaled.     

Ceric Ammonium Nitrate Catalysed Protection of Alcohols by 3, 4-Dihydro-2H-pyran

Hydroxyl compounds readily add to dihydropyran in presence of a catalytic amount of ceric ammonium nitrate to give high yield of tetrahydropyranyl ethers.     

Evidence for Atropisomerism in Polycyclic γ-Butenolides: Synthesis,Scope, and Spectroscopic Studies

Design and development of a domino cyclative approach for the synthesis of new polycyclic γ-butenolides from β-aryl-Z-enoate propargylic alcohols, through the interception of an intermediate of the Z-enoate-assisted Meyer–Schuster rearrangement, has been reported. A systematic NMR analysis of various derivatives of this class revealed and supported the potential atropisomerism associated with them. These molecules represent first examples of butenolide ring-based atropisomeric compounds in organic chemistry. The synthetic process involves a synchronous construction of both rings with concurrent creation of the potential stereogenic rotational axis.     

Therapeutics for COVID-19: from computation to practices—where we are,where we are heading to

Molecular Diversity - After the 1918 Spanish Flu pandemic caused by the H1N1 virus, the recent coronavirus disease 2019 (COVID-19) brought us to the time of serious global health catastrophe....     

Random Latin squares and 2-dimensional expanders

Expander graphs have been playing an important role in combinatorics and computer science over the last four decades. In recent years a theory of high dimensional expanders is emerging, but as of now all known examples of expanders (random and explicit) have unbounded degrees. The question of existence of bounded degree high dimensional expanders was raised by Gromov and by Dotterrer and Kahle. In this paper we present a new model, based on Latin squares, of 2-dimensional complexes of bounded edge degrees that are expanders with probability tending to 1.