Prepared Sulfonic-Acid-Based Ionic Liquid for Catalytic Conversion of Furfuryl Alcohol to Ethyl Levulinate.

Efficient utilization of Brønsted acids has been advanced through the synthesis of a novel pyridinium propyl sulfonic acid ionic liquid catalyst, [PSna][HSO4]. Employing niacin and 1,3-propanesulfonic lactone, the synthesis aimed to achieve a catalyst that combines atom-efficiency with stability. Optimal catalytic activity was demonstrated at a temperature of 110 °C over a 2 h reaction time, resulting in a furfuryl alcohol conversion and ethyl levulinate yield of 97.79% and 96.10%, respectively. Notably, the extraction and recovery of [PSna][HSO4] exhibited commendable repeatability with up to five cycles, maintaining furfuryl alcohol conversion and ethyl levulinate yield at 93.74% and 88.17%, which highlights the catalyst's durability. Density flooding theory (DFT) calculations were employed to determine the most probable reaction pathways and identify all possible transition states and the reaction energy barriers overcome at each step of the reaction.

Alcoholysis of Furfuryl Alcohol to Ethyl Levulinate Catalyzed by a Deep Eutectic Solvent.

In this study, the alcoholysis of furfuryl alcohol (FA) into ethyl levulinate (EL) using a deep eutectic solvent (DES) composed of choline chloride (ChCl) and ethanol was investigated by experiments and calculations. Experimental results reveal that the addition of 5-sulfonic acid salicylic acid (5-SSA) can catalyze the alcoholysis of FA to produce EL. The combined presence of ChCl and 5-SSA significantly improved the selectivity for EL. The mechanism of the alcoholysis of FA to EL in acidic DES was investigated by density functional theory (DFT) calculations in Gaussian 03. It was found that hydrogen-bond acceptor ChCl is coupled with hydrogen-bond donor ethanol to form a structure similar to HCl and ethoxy, which facilitates the alcoholysis of FA into EL.

4,4'-(Ethene-1,2-di-yl)dipyridinium 4-[2-(pyridin-4-yl)ethen-yl]pyridinium octa-cyanidomolybdate(V) tetra-hydrate.

The crystal structure of the title compound, (C12H12N2)(C12H11N2)[Mo(CN)8]·4H2O, consists of 4,4'-(ethene-1,2-di-yl)dipyridinium and 4-[2-(pyridin-4-yl)ethen-yl]pyridinium cations disordered over the same site, an [Mo(CN)8](3-) anion and four water mol-ecules of crystallization. The eight-coordinate [Mo(CN)8](3-) unit exhibits a slightly distorted square-anti-prismatic geometry. In the structure, the cations (crystallographic symmetry, 2) and anions (crystallographic symmetry, 222) are arranged alternately by N-H⋯O and O-H⋯N hydrogen bonds, forming layers parallel to the bc plane. These layers are further linked through O-H⋯N hydrogen bonds, generating a three-dimensional supra-molecular network.

Tris(3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium) hexa-cyanidocobaltate(III) penta-hydrate.

The structure of the title compound, (C16H17N2)3[Co(CN)6]·5H2O, consists of three 3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium cations, a [Co(CN)6](3-) anion and five water mol-ecules of crystallization, one of which is disordered over two sets of sites in a 0.587 (15):0.413 (15) ratio. The [Co(CN)6](3-) anion exhibits an octa-hedral geometry. In the structure, cations and anions are linked alternatively through O-H⋯O, O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds, π-π inter-actions [centroid-centroid distances = 3.523 (2)-4.099 (2) Å] and van der Waals forces, forming a three-dimensional supra-molecular network.

[Effect of surface modified nano-diamond on viscosity of dental adhesives].

PURPOSE: Different surface modified ultrafine-diamond (UFD) was added into dental adhesives as filler ,then the influence of dental adhesive properties was observed. The main matrix of dental adhesive was high polymer resin. METHODS: Different content of non-modified UFD(n-UFD) or modified UFD(m-UFD) were added into dental adhesives, then the viscosity of materials were measured. The data was processed with SPSS17.0 software package. RESULTS: The viscosity of dental adhesives was decreased when the proportion of UFD was less than 0.1wt%, especially when it was 0.1wt%; but was significantly improved when the proportion was more than 0.1wt%. The effect of UFD and surface-modified UFD on the viscosity was significantly different. CONCLUSIONS: The results show that silane coupling was chemically-grafted on the surface of UFD, the dispersion and stability of UFD in ethanol was improved; And a quantity of UFD with special content could reduce the viscosity of dental adhesives and improve the flowability obviously. The m-UFD was superior to n-UFD.