Alcohol Molecules Research Articles

Dynamics of collisions and uptake of alcohol molecules with hydrated nitric acid clusters.

We investigate the collisions of different alcohol molecules with hydrated nitric acid clusters using a molecular beam experiment and molecular dynamics simulations. The uptake cross sections σp for the molecules evaluated from the experiment are in excellent agreement with the simulations. This suggests that (i) the nontrivial assumptions implemented in the evaluation procedure of the experimental data are valid, and (ii) the simulations describe correctly the major processes in the molecule-cluster collisions. We observe that σp decreases with the increasing alkyl chain length of the alcohol, and also with the branching of the molecules that have the same mass but different structures. These systematic trends can be rationalized based on the accessibility of the hydrophilic OH group, which decreases with the increasing chain length and steric hindrance. The observed trends and their interpretation differ significantly from the simple model of hard-sphere collisions. The obtained data shall be beneficial not only for the fundamental understanding of the molecule-cluster collisions, but also in the modelling of atmospheric new-particle formation and aerosol growth.

The Synergistic Influence of the Hydrophobic and Hydrophilic Ends on the Primary Dielectric Relaxation Rate of Methanol

The primary dielectric relaxation process of monoalcohols typically exhibits characteristic Debye behavior, and the factors influencing its rate have become a research focus in recent years. It is generally believed that the hydrophilic end (i.e., the hydroxyl group) of alcohol molecules plays a major role in the primary dielectric relaxation process through hydrogen bonding networks, while the hydrophobic end mainly exerts an indirect effect by influencing the formation of intermolecular hydrogen bonds. This study systematically investigates the factors influencing the primary dielectric relaxation process of methanol using molecular dynamics simulations. As the simplest alcohol molecule, studying methanol can provide insights into the common characteristics of monohydroxy alcohols and even alcohols in general. The well-known "wait-and-switch" model currently emphasizes the impact of hydrogen bond partner concentration on the primary dielectric relaxation rate of the system. In this study, we systematically investigated the factors influencing the primary dielectric relaxation rate of methanol by independently adjusting the O-H bond length (<i>d<sub>oh</sub></i>), the C-O bond length (<i>d<sub>oc</sub></i>), and the methyl diameter (<i>σ<sub>methyl</sub></i>) of methanol molecules, and provided significant extensions to the "wait-and-switch" model:1) By adjusting <i>doh</i>, we found that a stronger total hydrogen bond energy (<i>U<sub>HB</sub></i>) in the system enhances the correlation of molecular motion, slowing down the reorientation rate of molecules and, consequently, the primary dielectric relaxation process of the system. 2) By adjusting <i>d<sub>co</sub></i>, we discovered that a longer hydrophobic end not only slows down the primary dielectric relaxation process by stabilizing the intermolecular hydrogen bond network but also directly reduces the rate of this process. 3) By adjusting <i>σ<sub>methyl</sub></i>, we found that an excessively small <i>σ<sub>methyl</sub></i> is detrimental to the stability of the hydrogen bond network, while an excessively large <i>σ<sub>methyl</sub></i> hinders the formation of hydrogen bonds. Both cases negatively affect the correlation of molecular motion. The primary dielectric relaxation process of the system is slowest when <i>σ<sub>methyl</sub></i> is at a moderate level. It was ultimately found that factors such as <i>U<sub>HB</sub></i> and the volume of the correlated motion (<i>V<sub>CM</sub></i>), along with the concentration of hydrogen bond partners in the system, collectively form the key elements influencing the primary dielectric relaxation rate of the system. Our results can reasonably explain experimental phenomena that the original "wait-and-switch" model could not account for. This study contributes to a deeper understanding of the relaxation processes of alcohol molecules and their physical origins.

Benchmarking the anisotropy of nitroxyl radical solvation with IR spectroscopy.

Two simple nitroxyl radicals, di-tert-butyl nitroxyl (DTBN) and 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) are solvated by one or two water, methanol, tert-butyl alcohol or phenol molecules. The resulting low temperature IR spectra of the vacuum-isolated microsolvates in the OH stretching range are assigned based on harmonic DFT predictions for closed shell solvent dimers and trimers and their offset from experiment, to minimise theory-guided assignment bias. Systematic conformational preferences for the first and second solvent molecule are observed, depending on the conformational rigidity of the radical. These assignments are collected into an experimental benchmark data set and used to assess the spectral predicting power of different DFT approaches. The goal is to find inexpensive computational methods which provide reliable spectral predictions for this poorly explored class of microsolvates.

Nanoscale solvent organization in metal-organic framework ZIF-8 probed by EPR of flexible β-phosphorylated nitroxides.

Metal-organic frameworks (MOFs) draw increasing attention as nanoenvironments for chemical reactions, especially in the field of catalysis. Knowing the specifics of MOF cavities is decisive in many of these cases; yet, obtaining them in situ remains very challenging. We report the first direct assessment of the apparent polarity and solvent organization inside MOF cavities using a dedicated structurally flexible spin probe. A stable β-phosphorylated nitroxide radical was incorporated into the cavities of a prospective MOF ZIF-8 in trace amounts. The spectroscopic properties of this probe depend on local polarity, structuredness, stiffness and cohesive pressure and can be precisely monitored by Electron Paramagnetic Resonance (EPR) spectroscopy. Using this approach, we have demonstrated experimentally that the cavities of bare ZIF-8 are sensed by guest molecules as highly non-polar inside. When various alcohols fill the cavities, remarkable self-organization of solvent molecules is observed leading to a higher apparent polarity in MOFs compared to the corresponding bulk alcohols. Accounting for such nanoorganization phenomena can be crucial for optimization of chemical reactions in MOFs, and the proposed methodology provides unique routes to study MOF cavities inside in situ, thus aiding in their various applications.

Blue ZnSeTe quantum dot light-emitting diodes with low efficiency roll-off enabled by an in situ hybridization of ZnMgO nanoparticles and amino alcohol molecules.

ZnSeTe quantum dots (QDs) have been employed as promising emitters for blue QD-based light-emitting diodes (QLEDs) due to their unique optoelectronic properties and environmental friendliness. However, such QLEDs usually suffer from serious efficiency roll-off primarily stemming from exciton loss at the interface of the QD layer and the ZnMgO (ZMO) electron transport layer (ETL), which remarkably hinders their application in flat-panel displays. Herein, we propose an in situ hybridization strategy that involves the pre-introduction of amino alcohols into the reaction solution. This strategy effectively suppresses the nucleophilic condensation process by facilitating the coordination of ammonium and hydroxyl groups with metal cations (M2+, i.e. Zn2+ and Mg2+). It slows down the growth rate of ZMO nanoparticles (NPs) while simultaneously facilitating M-O coordination, resulting in the synthesis of small-sized and low-defect ZMO NPs. Notably, this in situ hybridization approach not only alleviates emission quenching at the QDs/ETL interface but also elevates the energy level of the ETL for enhancing carrier injection. We further investigated the impact of amino alcohols with varying carbon-chain lengths on the performance of ZMO NPs and the corresponding LED devices. The optimal blue ZnSeTe QLED demonstrates an impressive EQE of 8.6% with only an ∼11% drop when the current density is increased to 200 mA cm-2, and the device operating lifetime extends to over 1300 h. Conversely, the device utilizing traditionally post-treated ZMO NPs as the ETL exhibits 45% efficiency roll-off and device lifetime of merely 190 h.

Effect of pH On Xylitol Composition- Preliminary Study

Xylitol is a sugar alcohol, its molecular structure is hybrids between the molecule of sugar and the molecule of alcohol. Xylitol can be used as a sugar substitute in human uptake especially diabetes because it does a minimal effect on the blood sugar level. The properties of xylitol can be modified to be suit to replace sugar. Therefore, the main purpose for this research studies was to find what modification can be made on xylitol properties so that it is suitable to substitute sugar for sugar uptake in human and to prove that not all the commercial xylitol can be used to substitute sugar. In this research the pH of the xylitol were changed to the suitable pH value. Then they were observed using UV-vis and FTIR to determine the changes on the composition of the modified xylitol.

Poly(vinyl alcohol)/ZSM-5 zeolite mixed matrix membranes for pervaporation dehydration of ethanol and n-propanol.

In this study, mixed matrix membranes (MMMs) composed of poly(vinyl alcohol) (PVA) and porous ZSM-5 zeolite are thoroughly investigated for concentrating alcohols of ethanol and n-propanol via dewatering pervaporation. The effects of the zeolite content (10-30 wt.%), feed composition (5-30 wt.% water), and feed temperature (50-90 °C) on the pervaporation flux/separation factor and component permeance/selectivity of these MMMs are examined in detail. These MMMs achieve higher separation efficiency and pervaporation flux than their pure PVA counterparts as expected, even if the dehydration results strongly depend on the pervaporation conditions. The disparity in pervaporation performances acquired for different alcohol solutions may be understood in terms of polarity and molecular size, which differ among these alcohol molecules. The PVA/zeolite MMM of 20 wt.% ZSM-5 zeolite content performs substantially stably at 60 °C for the feed with 80 wt.% alcohol while maintaining separation factors of 660 or 820 and total fluxes of 970 or 825 g/m2h for dewatering water/ethanol and water/n-propanol, respectively. Thus, our membranes appear to be technically feasible for practical alcohol dehydration uses.

Modelling of structure and concentration characteristics of water-alcohol solutions

Water-alcohol solutions are widely used in pharmacy, food industry, engineering, etc. The study of their physical and chemical properties has a long history. Nevertheless, due to the complexity of these systems, there is still an interest in their research stimulated by the development of biochemistry in terms of the study and protection of the environment, global climate change, renewable energy resources and cosmochemistry. The purpose of the presented study is the quantum-chemical investigation of water clusters with methyl and ethyl alcohol molecules, as well as the modelling of concentration dependences of the excess molar volume of ethyl alcohol solution in water at different temperatures. Based on quantum-chemical calculations of paired and mixed complexes of water with methanol and ethanol, taking into account solvation effects, study reveals the formation of thermodynamically efficient complexes in liquid, in contrast to the ideal gas state, while in the mixture both individual solvated alcohol molecules and complexes will be in equilibrium. We noted a relative difference in the free energies of solvation of paired and mixed methanol and ethanol complexes. The paper proposes a technique for calculating the excess molar volume in water-alcohol mixtures by approximating the experimental dependences by Lejandre polynomials of the ninth degree. The calculation results showed high accuracy. Hence, continuous functions describe the dependences of the calculated coefficients of Lejandre polynomials on temperature.

Моделирование структуры и концентрационных характеристик водно-спиртовых растворов

Water-alcohol solutions are widely used in pharmacy, food industry, engineering, etc. The study of their physical and chemical properties has a long history. Nevertheless, due to the complexity of these systems, there is still an interest in their research stimulated by the development of biochemistry in terms of the study and protection of the environment, global climate change, renewable energy resources and cosmochemistry. The purpose of the presented study is the quantum-chemical investigation of water clusters with methyl and ethyl alcohol molecules, as well as the modelling of concentration dependences of the excess molar volume of ethyl alcohol solution in water at different temperatures. Based on quantum-chemical calculations of paired and mixed complexes of water with methanol and ethanol, taking into account solvation effects, study reveals the formation of thermodynamically efficient complexes in liquid, in contrast to the ideal gas state, while in the mixture both individual solvated alcohol molecules and complexes will be in equilibrium. We noted a relative difference in the free energies of solvation of paired and mixed methanol and ethanol complexes. The paper proposes a technique for calculating the excess molar volume in water-alcohol mixtures by approximating the experimental dependences by Lejandre polynomials of the ninth degree. The calculation results showed high accuracy. Hence, continuous functions describe the dependences of the calculated coefficients of Lejandre polynomials on temperature.

Study on the Design of Electrocatalysts for Polymer Electrolysis in the Aqueous Solution

Now, most plastic recycling is thermal recycling by incineration. As a matter of course, thermal recycling is not a sustainable recycling method for plastic material. Material recycling is being carried out in which some used plastics are molded and reused.[1] However, material recycling has the problem that cannot separate the pigments and dyes. This problem causes the limitation of color and quality degradation in the recycling of plastics. Therefore, we focused on the depolymerization and re-polymerization between polymers and monomers by electrolysis in order to develop a new recycling method without degrading the quality of the plastics.Since most polymers are insulator materials, there has been almost no report about polymer electrolysis, and the electrochemical behavior is also unknown. [2, 3] We investigated to obtain basic information for the electrolysis of polymers, a monovalent alcohol molecule bonded to the terminal or side chain and a divalent alcohol molecule bonded to both ends were used as the model molecule, and their electrochemical behavior was investigated. In addition, electrolysis of PVA and PEG, which have similar structures to alcohol molecules, was conducted as the first step of depolymerization into monomers. In the case of PEG, the oxidation current, which may be attributed to the decomposition, was observed. In contrast, the decomposition behavior of PVA was not confirmed. Their results suggested that the oxidation of polymer may favor the presence of other atoms, such as oxygen, at the main chain rather than the functional group at the side chain. Nylon66, which had nitrogen atoms at the main chain, also showed oxidation currents. However, Nylon66 was only oxidized by the iron-based catalyst. Iron should form the surface oxide layer at the oxidation potential of Nylon66. However, it doesn’t understand whether metal or metal oxide is suitable for the electrolysis of polymer materials. This study electrolyzed Nylon66 using Ti foil and Ru and RuO2 powder to consider whether metal or oxide was suitable for polymer electrolysis.The electrochemical cell was composed of a working electrode, a carbon counter electrode, a reversible hydrogen electrode (RHE) as a reference electrode, and 0.2 M NaOH. Cyclic voltammetry (CV) was conducted at room temperature in an inert atmosphere, and the scan rate was 50 mV s-1. Nylon66 was polymerized on the working electrode directly. Furthermore, before and after electrolysis, its molecular structure and electronic state on the electrode surface were confirmed by Raman and XPS.All test catalysts in this study showed the oxidation current of Nylon66 around 1.2 V only in the first cycle. RuO2 demonstrated relatively high oxidation currents compared with other catalysts. In addition, Ti foil formed a thick oxide layer at the surface during CV measurement.After electrolysis, the Raman spectrum of the Ti foil surface indicated that the C-O-C stretch vibration mode, which did not include in Nylon66, was observed. On the other hand, Ru and RuO2 did not generate new vibrational modes. However, the results of XPS suggested that the sp2 carbon species, C=C bonds, increased in all catalysts. Thus, Nylon66 was probably decomposed. Interestingly, Ru0 species were observed in RuO2 after electrolysis. This result meant RuO2 was partially reduced during electrolysis. It is thought that the lattice oxygen in the RuO2 crystal was possibly consumed by Nylon66 oxidation. The above results indicate that the lattice oxygen of oxide should play an important role in polymer electrolysis. In this study, electrolysis of Nylon66 was performed using Ti and Ru, RuO2 electrocatalysts. Each catalyst, the oxidation current was observed only in the first cycle. The results of Raman and XPS suggested the partial decomposition of Nylonn66 in all catalysts. It was concluded that the presence of lattice oxygen in oxide is one of the keys to polymer electrolysis, and the metal oxide may be suitable as an electrocatalyst.[1] T. Kamo, Science of the Field, 1, (2021) 28-44.[2] O. R. Luca et al. Molecules, 25 (2020) 1-9.[3] T. Jiang et al. Solar Energy Materials & Solar Cells, 204 (2020) 1-10.

Structure of tert-butyl alcohol in carbon tetrachloride solution. Molecular dynamics simulation study

The structure of tert-butyl alcohol (TBA) solution in carbon tetrachloride (CCl4) is studied over the entire concentration range using molecular dynamics simulation (MD). It is shown that at low alcohol concentrations (within 5% molar fraction), separate small associates of TBA appear as a result of hydrogen bonding between alcohol molecules, and cyclic structures of four TBA molecules appear among these associates. With increasing concentration, the formation of hydrogen-bonded associates quickly reaches its limit corresponding to 1.7 bonds per molecule as in pure TBA. At high alcohol concentrations, both linear and cyclic associates of TBA molecules are observed with a noticeable fraction of cyclic tetramers. Using the Voronoi method, aggregates of the nearest TBA molecules are considered. The number and size of such aggregates grows rapidly with concentration due to the presence of “nuclei” formed by hydrogen bonding. At an alcohol mole fraction of 15%, a percolation cluster of TBA molecules begins to form in the solution. On the contrary, in the local environment of CCl4 molecules no significant structural rearrangements occur, only a gradual replacement of the molecules is observed upon addition of alcohol. However at low content of CCl4 in alcohol, we can see some tendency to clustering of CCl4 molecules, which may indicate on a slight solvophobic effect in this solution.

New Protocol for the Synthesis of S-Thioesters from Benzylic, Allylic and Tertiary Alcohols with Thioacetic Acid.

A new one-pot solvent-less reaction to convert benzylic, allylic, ferrocenyl or tertiary alcohols into S-thioesters, bench-stable and less odorous precursors of the corresponding thiols, which is based on reactions in neat thioacetic acid in the presence of tetrafluoroboric acid, is presented. Reaction monitoring by NMR and GC of the benzyl alcohol conversion indicated the intermediate formation of benzyl acetate and benzyl thionoacetate (PhCH2 OC(S)CH3 ) prior to the slower conversion to the final S-benzyl thioacetate product. Increasing the HBF4 concentration enhanced the reaction rate, giving good to excellent yield (up to 99 %) for a large scope of alcohols. Control experiments, with support of DFT calculations, have revealed a thermodynamically favorable, though requiring HBF4 -activation, disproportionation of CH3 C(O)SH to CH3 C(O)OH and CH3 C(S)SH, the latter immediately decomposing to H2 S and (MeC)4 S6 but also generating the hitherto unreported [MeC(O)C(Me)S]2 (μ-S)2 . Kinetic investigations demonstrated that the rate of benzyl alcohol conversion is second-order in [PhCH2 OH] and second order in [HBF4 ], while the rate of conversion of the benzyl acetate intermediate to S-benzyl thioacetate is second order in [PhCOOMe] and fourth order in [HBF4 ]. The DFT calculations rationalize the need to two alcohol molecules and two protons to generate the reactive benzyl cation.

Antiparasitic effect of Farnesol against Leishmania major: A rationale from in vitro and in silico investigations.

Leishmaniasis is a vector-borne parasitic infection caused by the infective bite of female Phlebotomine sandflies. Treatment of leishmaniasis by conventional synthetic compounds is met by challenges pertaining to adverse effects which call for the discovery of newer anti-leishmanial molecules. This study was performed to evaluate the effect and modes of action of a sesquiterpene alcoholic molecule Farnesol on Leishmania major, the causative agent of Zoonotic CL. The cytotoxic effect of Farnesol against L.major promastigotes, amastigotes and macrophages was assessed by MTT test and counting. The IC50 on promastigotes by Farnesol on L.major was also evaluated by flow cytometry. In the findings, promastigotes were reduced at 167μM. The mean numbers of L.major amastigotes in macrophages were significantly decreased on exposure to Farnesol at 172μM. In addition, Farnesol induced significant apoptosis dose-dependent on L.major promastigotes. In silico protein-ligand_binding analyses indicated the effect of Farnesol in perturbation of the ergosterol synthesis pathway of Leishmania with attributes suggesting inhibition of Lanosterol-α-demethylase, the terminal enzyme of ergosterol synthesis machinery. Findings from flow cytometry reveal the role of Farnesol in apoptosis-induced killing in promastigotes. Farnesol was effective at very lower concentrations when compared to Paromomycin. Further studies are crucial to evaluate the therapeutic potential of Farnesol alone or in combination with other conventional drugs in animal models.

Effects of alcohols and dissolved gases on sonochemical generation of hydrogen in a 300 kHz sonoreactor

The sonochemical generation of hydrogen (H2) was investigated using various water/alcohol solutions under argon (Ar) 100 % in a 300 kHz sonoreactor. Five types of alcohols–methanol, ethanol, isopropanol, n-propanol, and n-butanol–were used at various concentrations (0 – 100 % v/v). The H2 generation rate in water was 0.31 μmol/min in the absence of alcohols. The H2 generation rate increased, peaked, and then decreased as the alcohol concentration increased. The concentrations used for the peak H2 generation were 5 %, 1 %, 0.5 %, 0.5 %, and 0.1 % for methanol, ethanol, isopropanol, n-propanol, and n-butanol, respectively. The highest generation rate (5.46 μmol/min) was obtained for methanol 5 % among all conditions in this study, and no H2 was detected for 100 % alcohol concentrations. The reason for the enhancement of the sonochemical H2 generation by the addition of alcohols might be due to strong scavenging effect of alcohols for sonochemically generated oxidizing radicals and vigorous reactions of alcohol molecules and their derivatives with H radicals. No significant correlations were found between the H2 generation rates and physicochemical properties of the alcohols in any of the data in this study. As alcohol concentration increased, the calorimetric power decreased. This indicates that the calorimetric power does not represent the degree of sonochemical reactions in the water/alcohol mixtures. The effect of oxygen (O2) content in the dissolved gases on the generation of H2O2 (representing sonochemical oxidation activity) and H2 (representing sonochemical reduction activity) was investigated using Ar/O2 mixtures for water, methanol 5 % and n-propanol 0.5 %. In water, the highest H2O2 generation was obtained for Ar/O2 (50:50), which is similar to previous research results. However, the H2O2 generation increased as the O2 content increased. In addition, H2 generation decreased as the O2 content increased under all liquid conditions (water, methanol, and n-propanol).

Mass spectrometric monitoring of ligand-bridged hot electron transfer and anaerobic oxidization on auto renewable droplet-based plasmonic nanoreactors under visible light illumination

The light induced hot-electron on plasmonic nanostructures has been recognized as a breakthrough discovery for photovoltaic and photocatalytic applications. With mass spectrometry, we demonstrate the dynamics of hot electron transfers of anaerobic oxidization reactions on Au decorated TiO2 plasmonic nanoparticles, which were coated on the inner surface of a flask. Those nanoparticles were covered by continuously renewed liquid droplets of solvent and reactants that were transported through a Venturi jet mixer with auto-spray. In addition to intensive mass transfer in such droplet-based nanoreactors, as well as strong adsorption of reactants and rapid desorption of products on materials surfaces, the localized surface plasmon resonance (LSPR) excitation upon visible light illumination, by which accumulated energies of plasmons are transferred to electrons in the conduction band of the material, attributes to the efficient photocatalytic transformation. Mass spectrometric detection of intermediate radical anions and negative ions with stable isotope labeling unambiguously identifies that highly energetic hot electrons can escape from the plasmonic nanostructures, be collected by adsorbed molecules, and initiate bond cleavages. It was demonstrated that losses of two H atoms result in the anaerobic oxidization of each benzyl alcohol molecule to a benzyl aldehyde molecule in the absence of molecular oxygen with more than 90 % yields. The well recyclable plasmonic nanoreactors implicate the injection of transferred electrons eventually back to electronically depleted Au+ positive ions. Bridged by adsorbed molecules, electrons were repeatedly circulated back and forth in plasmonic nanoreactors, where the collected light was eventually converted into chemical energy.

Hydration behaviour of cement in polymer cement waterproof coating and its effect on the macroscopic performance

In polymer-cement waterproof coating systems, the polymer emulsion influences the hydration behaviour of the cement component, which in turn affects the macroscopic performance of the coating. In this study, the effects of styrene–acrylate (SA), vinyl acetate copolymer emulsion (VAE), and styrene–butadiene (SB) emulsions on the hydration behaviour of cement and macroscopic properties of waterproofing coatings were investigated through chemical binding water testing; thermogravimetric, X-ray diffraction X-ray photoelectron spectroscopy, and Fourier transform infrared microscopic analyses; and macroscopic property characterisation. Moreover, the mechanism of the chemical reaction between the emulsion and cement was clarified. The degree of cement hydration is the least and most affected by the SB and VAE emulsions, respectively. When the cement proportion in the inorganic phase is 50%, the hydration degree of cement in cases involving SA, VAE, and SB emulsions is 24.87%, 19.57%, and 28.61%, respectively. As the cement proportion in the powder phase increases, the tensile strength and bond strength of the polymer cement waterproof coating increase and the elongation at break decreases. The rate of increase of the tensile strength and rate of decrease of the elongation at break both decrease after the cement content becomes 50%. The SA emulsion complexes with the calcium ions in the hydrated environment, which enhances the interfacial bonding between the organic and inorganic phases and results in excellent macroscopic performance of SA waterproof coatings. The SB emulsion waterproof coating has the best mechanical properties and highest water resistance owing to the highest degree of hydration of cement under the action of SB emulsion and hydrophobicity of the emulsion. The VAE emulsion generates hydrophilic polyvinyl-vinyl alcohol and small molecule products that easily dissolve in alkaline hydration environments, leading to low water resistance of the corresponding waterproof coating.

Effect of Chain Length on Swelling Transitions of Brodie Graphite Oxide in Liquid 1‐Alcohols

AbstractSwelling is the most fundamental property of graphite oxides (GO). Here, a structural study of Brodie graphite oxide (BGO) swelling in a set of long chain 1‐alcohols (named C11 to C22 according to the number of carbons) performed using synchrotron radiation X‐ray diffraction at elevated temperatures is reported. Even the longest of tested alcohols (C22) is found to intercalate BGO with enormous expansion of the interlayer distance from ≈6Å up to ≈63Å, the highest expansion of GO lattice ever reported. Swelling transitions from low temperature α‐phase to high temperature β‐phase are found for BGO in all alcohols in the C11–C22 set. The transitions correspond to decrease of inter‐layer distance correlating with the length of alcohol molecules, and change in their orientation from perpendicular to GO planes to layered parallel to GO (Type II transitions). These transitions are very different compared to BGO swelling transitions (Type I) found in smaller alcohols and related to insertion/de‐insertion of additional layer of alcohol parallel to GO. Analysis of general trends in the whole set of 1‐alcohols (C1 to C22) shows that the 1‐alcohol chain length defines the type of swelling transition with Type I found for alcohols with C<10 and Type II for C>10.

Evaluation of infrared spectroscopic methods for the study of structural properties of liquid alcohols

This work aims to evaluate the infrared spectroscopic methods for the study of the structural properties of liquid alcohols – specifically how many alcohol molecules and how many hydroxyl groups do not participate in hydrogen bonds as donors. They are known as monomer fractions and free hydroxyl group fractions, respectively, in the community of chemical engineering thermodynamics. The infrared spectra processing methodologies for the extraction of free hydroxyl groups/monomer fractions in 1-alcohol solutions at various temperatures and their assumptions are discussed extensively in a comprehensive manner. The application of these methods addresses the surprising conclusion of literature experimental data that indicated identical behavior of methanol and ethanol in terms of liquid structural properties over a wide range of temperatures. A discrepancy is observed in data regarding saturated liquid methanol and ethanol, which shows that methanol indeed exhibits a stronger association than ethanol, as expected, at higher temperatures. The difficulties in the interpretation of liquid alcohol infrared spectra are further demonstrated in the case of 1-octanol, where evidence indicates that an association scheme which considers branched clusters is more consistent, especially in the region of low free hydroxyl fractions.

Achieving High-Performance Electrocatalytic Water Oxidation on Ni(OH)2 with Optimized Intermediate Binding Energy Enabled by S-Doping and CeO2 -Interfacing.

The adsorption energy of the reaction intermediates has a crucial influence on the electrocatalytic activity. Ni-based materials possess high oxygen evolution reaction (OER) performance in alkaline, however too strong binding of *OH and high energy barrier of the rate-determining step (RDS) severely limit their OER activity. Herein, a facile strategy is shown to fabricate novel vertical nanorod-like arrays hybrid structure with the interface contact of S-doped Ni(OH)2 and CeO2 in situ grown on Ni foam (S-Ni(OH)2 /CeO2 /NF) through a one-pot route. The alcohol molecules oxidation reaction experiments and theoretical calculations demonstrate that S-doping and CeO2 -interfacing significantly modulate the binding energies of OER intermediates toward optimal value and reduce the energy barrier of the RDS, contributing to remarkable OER activity for S-Ni(OH)2 /CeO2 /NF with an ultralow overpotential of 196mV at 10mA cm-2 and long-term durability over 150h for the OER. This work offers an efficient doping and interfacing strategy to tune the binding energy of the OER intermediates for obtaining high-performance electrocatalysts.

Plasmon-Induced Radical-Radical Heterocoupling Boosts Photodriven Oxidative Esterification of Benzyl Alcohol over Nitrogen-Doped Carbon-Encapsulated Cobalt Nanoparticles.

Selective oxidation of alcohols under mild conditions remains a long-standing challenge in the bulk and fine chemical industry, which usually requires environmentally unfriendly oxidants and bases that are difficult to separate. Here, a plasmonic catalyst of nitrogen-doped carbon-encapsulated metallic Co nanoparticles (Co@NC) with an excellent catalytic activity towards selective oxidation of alcohols is demonstrated. With light as only energy input, the plasmonic Co@NC catalyst effectively operates via combining action of the localized surface-plasmon resonance (LSPR) and the photothermal effects to achieve a factor of 7.8 times improvement compared with the activity of thermocatalysis. A high turnover frequency (TOF) of 15.6 h-1 is obtained under base-free conditions, which surpasses all the reported catalytic performances of thermocatalytic analogues in the literature. Detailed characterization reveals that the d states of metallic Co gain the absorbed light energy, so the excitation of interband d-to-s transitions generates energetic electrons. LSPR-mediated charge injection to the Co@NC surface activates molecular oxygen and alcohol molecules adsorbed on its surface to generate the corresponding radical species (e.g., ⋅O2 - , CH3 O⋅ and R-⋅CH-OH). The formation of multi-type radical species creates a direct and forward pathway of oxidative esterification of benzyl alcohol to speed up the production of esters.