d-d Orbital coupling induced by crystal-phase engineering assists acetonitrile electroreduction to ethylamine

The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.

Extractive distillation of the benzene and acetonitrile mixture using an ionic liquid as the entrainer

The benzene and acetonitrile azeotropic mixture was proposed to be separated by extractive distillation using an ionic liquid(IL)as the entrainer.The suitable IL was selected by the COSMO-RS model,and 1-ethyl-3-methylimidazolium tetrafluoroborate([EMIM][BF_(4)])was considered as the suitable entrainer mainly due to its high selectivity,low viscosity,and low price.The experimental vapor pressure data of the IL-containing systems(benzene+[EMIM][BF_(4)]and acetonitrile+[EMIM][BF_(4)])were measured in the full concentration range.The results show that acetonitrile has a stronger interaction with IL than benzene,and the low deviations between the experimental and UNIFAC predicted values show the reliability of the UNFIAC model.The UNIFAC predicted vapor-liquid equilibrium data of the benzene+acetonitrile+dimethyl sulfoxide(DMSO)/[EMIM][BF_(4)]system show that the relative volatility of benzene to acetonitrile is higher when the entrainer is[EMIM][BF_(4)].The process simulation results show that[EMIM][BF_(4)]can reduce the material and energy consumptions compared with DMSO.

Temperature and Pressure Behaviours of Methanol, Acetonitrile/Water Mixtures on Chromatographic Systems

Temperature and pressure were shown to vary significantly with solvent mixing, showing maxima at differ-ent solvent ratios. Acetonitrile/water mixing resulted in temperature reduction of solutions whereas metha-nol/water mixing caused temperature increases. On the other hand, maximum recorded chromatographic pressure of acetonitrile:water mixtures occurred at a solvent ratio of 1:6 compared with methanol:water, which showed a maximum pressure at a solvent ratio of 1:1. These findings can be of use in stabilizing re-tention time shifts during HPLC-based studies associated with compound identification based on retention time such as analysis of complex mixtures.

Determination of Acetonitrile Volume Fraction in Mobile Phase by HPLC

This paper reports the development and validation of an assay for the determination of acetonitrile in the recycled mobile phase using high performance liquid chromatography（HPLC）. The method is based on that the retention in reversed-phase liquid chromatography increases with decreasing concentration of organic phase in the mobile phase. The natural logarithm of the capacity ratio for a given solute is linearly related to the volume fraction of the organic modifier in the mobile phase. For dimethylphthalate and diethylphthalate, the linearity range is 30%--60%, and for biphenyl and terphenyl, the range is 60%--95%. Precision values（RSD） were both 〈1% and the accuracy（RE） was in the range of ±1%. The assay was successfully applied to the determination of acetonitrile concentration of recycled mobile phase after the distillation of the column eluent in our laboratory.

Comparison of Extractive Distillation and Pressure-Swing Distillation for Methanol and Acetonitrile Separation

In the present work,a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile separation is performed for the first time.Different separation alternatives,including the conventional extractive distillation,the extractive distillation with vapor or liquid side-stream,the pressure-swing distillation with or without full heat integration,and the heat-pump assisted pressure-swing distillation are rigorously simulated and optimized based on the minimum total annual cost(TAC)via the sequential iterative strategy.The results show that TAC and CO2 emission of the new extractive distillation with vapor side-stream(Vapor-SED)are similar to those of the extractive distillation with liquid side-stream(Liquid-SED).Furthermore,the Vapor-SED and Liquid-SED can achieve 30.01%and 30.56%reduction in TAC and 23.32%and 23.49%reduction in CO2 emission,respectively,over the most competitive fully heat-integrated PSD configuration.Hence,the extractive distillation with vapor or liquid side-stream appears to be a better option economically and environmentally for the separation of methanol and acetonitrile.

Treatment of Acetonitrile by Catalytic Supercritical Water Oxidation in Compact-Sized Reactor

The objective of this research was to study the treatment of acetonitrile by catalytic supercritical water oxi-dation in a compact-sized tubular reactor, with an internal volume of 4.71 mL. Manganese dioxide was used as the catalyst and H2O2 was used as the oxidant. The oxidation of acetonitrile in supercritical water was studied at 400-500 oC, 25-35 MPa, the flow rate of 2-4 mL/min, the initial concentration of acetonitrile 0.077-0.121 M and the %excess O2 of 50-200%. As a result, the products were mainly N2, CO2 and CO and acetonitrile can be decomposed > 93 % within a very short contact time (1.45-6.19 s). The oxidation process was carried out with respect to the conversion of acetonitrile by 25 factorial design. Regression models were obtained for correlating the conversion of acetonitrile with temperature and flow rate. The complete oxida-tion can be achieved at a condition as moderate as 400 oC, 25 MPa with the flow rate of 2 mL/min.

Acetonitrile(CH_3CN)and methyl isocyanide(CH_3NC) adsorption on Pt(111)surface:a DFT study

The adsorption of CH3CN and CH3NC on the Pt(111)surface at the 1/4 monolayer(ML)coverage has been carried out at the level of density functional theory for understanding hydrogenation processes of nitriles.The most favored adsorption structure for CH3CN is the C-N bond almost parallel to the surface with the C-N bond interaction with adjacent surface Pt atoms.For CH3NC,the most stable configuration is the CH3NC locates at the face center cubic(fcc)site with the C-atom bonded to three Pt atoms.In addition,the HCN and HNC adsorption has been computed,and the adsorption pattern is nearly similar to the CH3CN and CH3NC,respectively.The adsorbed molecules rehybridize on the surface,becoming non-linear with a bent C-C-N or C-N-C angle.Furthermore,the binding mechanism of these molecules on the Pt(111)surface is also analyzed.

Solar Thermochemical Reactions IV: Unusual Reaction of Nitrones with Acetonitrile Derivatives Induced by Solar Thermal Energy

The behaviour of cyanothioacetamide 1 and the acetonitrile derivatives 6 and 10, respectively, towards the nitrones 2a-i induced by free solar thermal energy is reported. Structures and reaction mechanisms are also discussed.

LASER FLASH SPECTROSCOPY STUDIES OF PYRENE EXCIMER IN ACETONITRILE

Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K.On the basis of these measurements,six rate parameters which describe the behaviour of pyrene excimer system in acetonitrile solution have been evaluated.At 355 nm laser light irradiation,the ΔG of the pyrene excimer formation in acetonitrile is evaluated to be -30.18kJ/mol. This value is quite different from the corresponding ΔG in cyclohexane (-16.72kJ/mol).

The d-orbital coupling modulation of CuNi alloy for acetonitrile electrochemical reduction and in-situ hydrogenation behavior characterization

Electrochemical reduction of acetonitrile to ethylamine with a high selectivity is a novel approach to manufacture valuable primary amines which are important raw material in organic chemical industry. However, the poor ethylamine Faradic efficiency(FE_(ethylamine)) and catalyst stability at the high current density prohibit this method from being practically used. Herein, CuNi alloy ultrafine-nano-particles based on the d-orbital coupling modulation were synthesized through the electrodeposition and their catalytic performance towards acetonitrile reduction reaction(ACNRR) has been systematically studied. The highest FE_(ethylamine)(97%) is achieved with the current density of-114 mA cm^(-2). For practical application, the current density can reach-602.8 mA cm^(-2) with 82.8% FE_(ethylamine)maintained. With the appearance of other organics which co-exist with acetonitrile in the SOHIO process, CuNi can also hydrogenate acetonitrile in it with more than 80% FE_(ethylamine). Our in-situ spectroscopy analysis and DFT calculations towards the acetonitrile hydrogenation behavior reveal that the evenly dispersed Ni in Cu modulates the dband so as to endow CuNi with the better acetonitrile adsorption, milder binding energy with the reaction intermediates, smaller barrier for *CH_3CH_2NH_2 desorption and higher ability for H_2O dissociation to provide *H.

High performance Zn-I_(2)battery with acetonitrile electrolyte working at low temperature

Large scale applications of metal-iodine batteries working at sub-zero degree have been challenged by the limited capacity and performance degradation.Herein,we firstly propose a Zn-I_(2)battery working at low temperature with a carbon composite material/iodine(CCM-I_(2))cathode,a Zn anode and an environmentally tolerable Zn(ClO4)2-ACN electrolyte.The CCM framework with hierarchical porous structure endows a powerful iodine-anchoring to overcome undesirable dissolution of iodine in organic electrolyte,and the Zn(ClO4)2-ACN electrolyte with low freezing point and high ionic conductivity enhances the low temperature performance.The synergies enable an efficiently reversible conversion of Zn-I_(2)battery even at-40℃.Therefore,the resultant Zn-I_(2)battery delivers a high specific capacity of 200 mAh·g^(-1),which is fairly approximate to the theoretical capacity of I_(2)(211 mAh·g^(-1))and a superior cycling stability with minimal capacity fading of 0.00043%per cycle over 7,000 times under 2C at-20℃.Furthermore,even at-40℃,this Zn-I_(2)battery still exhibits a good capacity retention of 68.7%compared to the capacity at 25℃ and a rapid capacity-recover ability with elevating temperature change.Our results distinctly indicate this Zn-I_(2)battery can be 1competent for the practical application under low temperature operation.

Triphenylamine pyridine acetonitrile fluorogens with green emission for pH sensing and application in cells

In this work,triphenylamine pyridine acetonitrile compounds Py A1,Py A2 and Py A3 are designed and synthesized.They show green fluorescence in water and bright emission in solid state.They have large Strokes shift（about 100 nm）.The excitation and emission spectra are investigated in ethyl acetate,chloroform,cyclohexane,ethanol,water,acetonitrile,THF,DMF and DMSO.It is interesting to find that these compounds are able to sense increasing pH values ranging from pH 2 to 7 by showing different color and emission intensities：almost no emission at pH 2 and strong green emission at pH 7.The acid–base switched color and fluorescence changes can be observed under UV irradiation,in water solution and 1% agarose gel.These changes can be repeated for several cycles.We are able to employ these compounds for cell pH environment imaging.

1D silver cluster-assembled materials act as a platform for selectively erasable photoluminescent switch of acetonitrile

A new 1D silver cluster-assembled complex Ag_(10)bpy-CH_3CN exhibiting intense photoluminescence was reported. Upon the loss of coordinated acetonitrile, Ag_(10)bpy-CH_3CN form Ag_(10)bpy with Ag_(10)S_6 cores slightly distorted, being accompanied with photoluminescence quenching. Inverse process can be realized by treating Ag_(10)bpy with acetonitrile and shows a selectively erasable photoluminescent switch.

In situ phosphonium-containing Lewis basecatalyzed 1,6-cyanation reaction:a facile way to obtainα-diaryl andα-triaryl acetonitriles

We present a phosphonium-containing catalyst generated in situ from phosphine and tert-butyl acrylate that serves as an unusual Lewis base catalyst.It was applied for the promotion of a remote 1,6-cyanation reaction of p-quinone methides and fuchsones employing trimethylsilyl cyanide as the cyanide source.A diverse range ofα-diaryl andα-triaryl acetonitriles was obtained in high yields under mild reaction conditions with low catalyst loading(5 mol%).The practicality and utility of this protocol were demonstrated via the gram-scale preparation and facile elaboration of products.Mechanistic investigations(in situ NMR and ESI-MS analysis)were employed to characterize the active zwitterionic phosphonium intermediate,which was the“true”active catalyst.

Determination of Triazine Herbicides in Environmental Water Samples by Acetonitrile Inorganic Salt Aqueous Two-Phase Microextraction System

Acetonitrile inorganic salt aqueous two-phase extraction method was established for the determination of triazine herbicides(simeton,cyanazine,desmetryn,terbumeton,terbuthylazine and dimethametryn)in environmental water samples by high-performance liquid chromatography(HPLC).The extraction solvents types and volume of acetonitrile,the inorganic salt types and amount of(NH_(4))_(2)SO_(4),extraction time and pH of sample solution were optimized by single-factor experiment and central composite design.Under the optimum extraction conditions,all linear ranges were obtained with coefficients of determination(r)≥0.9993.The limits of detection for this proposed method were in the range of 0.16-0.28μg/L for six triazine herbicides.The developed method has been successfully applied to the analysis of target triazine herbicides from lake,canal and moat in real-world water samples.The recoveries of target analytes were in the range from 87.0 to 110.9%and the relative standard deviation was lower than 7.3%.

A Concise Synthesis of 2-(2-Hydroxyphenyl)acetonitriles via the o-Quinone Methides Generated from 2-(1-Tosylalkyl)phenols

A concise synthesis of 2-(2-hydroxyphenyl)acetonitriles has been developed through reaction of trimethylsilyl cyanide and the o-quinone methides in situ generated from 2-(1-tosylalkyl)phenols under basic conditions.In addition,2-(2-hydroxyphenyl)acetonitriles could be conveniently transformed to benzofuranones.

Solubility of stearic acid in supercritical CO_2-acetonitrile mixtures

The solubility of stearic acid in supercritical CO2 with acetonitrile (CH3CN) cosolvent was measured at 318.15 K in the pressure range from 9.5 to 16.5 MPa, and the cosolvent concentration ranges from 0. 0 to 5.5 mol% . The solubility increases with acetonitrile concentration and pressure, and it also increases with the apparent density of CO2 d1(moles of CO2 in per liter of fluid) at higher cosolvent concentrations. At lower d1, however, the solubility of the acid at lower acetonitrile concentrations is lower than that in pure CO2 provided that d1 is fixed, which is discussed qualitatively based on the clustering of the components in the system.

Ultrafast Third-Order Optical Nonlinearity of Organic Solvents Investigated by Subpicosecond Transient Optical Kerr Effect

A femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents acetone,acetonitrile,alcohol,benzene,chloroform,dichlomathane,dimenthyl-sulfoxande,dioxane,ethanol,and methanol,etc.The nonlinear refractive index for the solvents at femtosecond time scale was measured.

A long-life and safe lithiated graphite-selenium cell with competitive gravimetric and volumetric energy densities

Lithium-selenium(Li-Se) battery is a promising system with high theoretical gravimetric and volumetric energy densities, while its long-term cyclability is hard to realize, especially when a practical Se cathode with high Se content, high Se loading, and high density is employed. The main obstacles are the sluggish conversion kinetics of the dense Se cathodes and the continuous deterioration of the Li-metal anodes.Here, by introducing an acetonitrile(AN)-based electrolyte and replacing the Li electrode with a lithiated graphite, we successfully build a hybrid conversion-intercalation system using a high-content(80 wt%),decent-loading(3.0 mg cm^(-2)), and low-porosity(44%) Se cathode. The as-designed lithiated graphite||Se(LG||Se) cell demonstrated a high Se utilization(97.4%), a long cycle life(3000 cycles), and an ultrahigh average Coulombic efficiency(99.98%). The cell also works well under lean-electrolyte(2 l L mg^(-1)) condition and shows outstanding safety performance in the nail-penetrating test. The combination affords the competitive comprehensive performances, including high volumetric and gravimetric energy densities, long cycling life, and superb safety of the LG||Se cell. In addition, with a newly-designed threeelectrode pouch cell, the lithiation of the graphite anodes could be done with an in-situ lithiation process,indicating the high potential of the as-proposed LG||Se cell for the practical applications.

Measurement Uncertainty Assessment of Magnesium Trisilicate Column for Determination of Sudan Colorants in Food by HPLC Using C8 Column

This study aimed to conduct measurement uncertainty assessment of a new method for determination of Sudan colorants（Sudan Ⅰ, Ⅱ, Ⅲ and Ⅳ） in food by high performance liquid chromatography（HPLC）. Samples were extracted with organic solvents（hexane, 20% acetone） and first purified by magnesium trisilicate（2Mg O·3Si O2）. The Sudan colorants（Sudan Ⅰ–Ⅳ） were also initially separated on C8 by gradient elution using acetonitrile and 0.1%（v/v） formic acid aqueous solution as the mobile phases and detected with diode-array detector（DAD）. The uncertainty of mathematical model of Sudan Ⅰ, Ⅱ, Ⅲ, Ⅳ is based on EURACHEM guidelines. The sources and components of uncertainty were calculated. The experiment gave a good linear relationship over the concentration from 0.4 to 4.0 μg/m L and spiked recoveries were from 74.0% to 97.5%. The limits of determination（LOD） were 48, 61, 36, 58 μg/kg for the four analytes, respectively. The total uncertainty of Sudan colorants（Sudan Ⅰ, Ⅱ, Ⅲ and Ⅳ） was 810±30.8, 790±28.4, 750±27.0, 730±50.0 μg/kg, respectively. The recovery uncertainty was the most significant factor contributing to the total uncertainty. The developed method is simple, rapid, and highly sensitive. It can be used for the determination of trace Sudan dyes in food samples. The sources of uncertainty have been identified and uncertainty components have been simplified and considered.