No abstract

New Zr(IV)- and Hf(IV)-based metal-organic framework photocatalysts, termed VNU-1 and VNU-2 (where VNU = Vietnam National University), were synthesized and their resulting structures fully characterized. By employing a highly π-conjugated linker, namely 1,4-bis(2-[4-carboxyphenyl]ethynyl)benzene, the optical absorption properties were effectively red-shifted into the visible light region. This strategy, coupled with the high water stability of the materials, led to enhanced MOF-driven photocatalytic degradation, under ultraviolet-visible light, of organic dye pollutants commonly found in wastewater.

A new superacid Hf-based MOF, termed VNU-11-P-SO4, was used as an efficient heterogeneous catalyst for solvent-free 2-arylbenzoxazole synthesis.

A novel and efficient methodology for the arylation of benzoxazoles with aromatic aldehydes catalyzed by deep eutectic solvent has been developed. The reaction smoothly proceeded with a wide range of substrates to give the desired products in high yields within short reaction time. Deep eutectic solvents are easily recovered and reused without significant loss of catalytic activity. Results and discussion Preparation and characterization of [ZnCl 2 ][ethylene glycol] 4DESs were synthesized by mixing zinc chloride and ethylene glycol (HBDs) at a dened molar ratio (1 : 4) and heating at 120 C for 1 h at atmospheric pressure under constant magnetic stirring until a homogeneous liquid was formed. The charge delocalization which occurs through hydrogen bonding between the halide anion and ethylene glycol is responsible for the decrease in the T m of the mixture. 52,53

A mild and highly efficient method for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a Lewis acidic deep eutectic solvent on magnetic nanoparticles (LADES@MNP).

An efficient and green method was developed for the acylation of secondary alcohols, phenols and naphthols using deep eutectic solvent [CholineCl][ZnCl2]3 as a catalyst at room temperature under solvent-free conditions.

An efficient and environmentally benign method for regio- and chemo-selective Friedel–Crafts acylation using deep eutectic solvent ([CholineCl][ZnCl2]3) under solvent-free microwave irradiation.

We have investigated the basicity of phosphinine (C5H5P, phosphabenzene) in reevaluating its proton affinity (PA) and gas-phase basicity (GB) and the pK(a) value of its protonated form. As a necessary step, we have first determined its gas-phase proton affinity. Using both mass spectrometric and quantum chemical methods, we have obtained the values PA(C5H5P) = 195.8 +/- 1.0 kcal mol(-1) and GB(298)(C5H5P) = 188.1 +/- 1.0 kcal mol(-1), in good agreement with previous results. We then derived a value of pK(a)(C5H6P+) = -16.1 +/- 1.0 in aqueous solution using three different approaches: the latter markedly differs from the currently available value of -10. The reason for such a discrepancy in the pK(a) of protonated phosphinine in solution is discussed. In the theoretical determination of PAs, evaluation of the basis set superposition error (BSSE) showed that this effect is quite small, being 0.1-0.2 kcal mol(-1) for phosphinine, when a density functional theory (DFT) method in conjunction with a large basis set were used.