Series Of Alcohols Research Articles

Nighttime reactions of a series of unsaturated alcohols with NO3•: Kinetics, products and mechanisms study

Unsaturated alcohols are a class of Biogenic volatile organic compounds (BVOCs) emitted in large quantities by plants when damaged or under adverse environmental conditions, and studies on their atmospheric degradation at night are still lacking. We used chamber experiments to study the gas-phase reactions of three unsaturated alcohols, E-2-penten-1-ol, Z-2-hexen-1-ol and Z-3-hepten-1-ol, with NO3 radicals (NO3•) during the night. The rate constants of these reactions were (11.7 ± 1.76) × 10−13, (8.55 ± 1.33) × 10−13 and (6.08 ± 0.47) × 10−13 cm3/(molecule·s) at 298K and 760 Torr, respectively. In contrast, the reaction rate of similar substances with ozone was about 10−18 cm3/(molecule·s), which indicates that the reaction with NO3• is the main oxidation pathway for unsaturated alcohols at night. Small molecule aldehydes and ketones were the main gas-phase organic products of the reaction of three aldehydes and ketones with NO3•, and the total small molecule aldehydes and ketones yields can reach between 45%-60%. They mainly originate from the breakage of alkoxy radicals, and different breakage sites determine different product distributions. In addition, the SOA yields of the three unsaturated alcohols with NO3• were 7.1% ± 1.0%, 12.5% ± 1.9% and 30.0% ± 4.5%, respectively, which were much higher than those of similarly structured substances with O3 or OH radicals (•OH). The results of high-resolution mass spectrometry shows that the main components of Secondary organic aerosol (SOA) of the three unsaturated alcohols are dimeric compounds containing several nitrate groups, which are formed through the polymerization of oxyalkyl radicals.

Inertization parameters for alcohols and ketones with nitrogen and carbon dioxide

A flammable fuel/air mixture can be successfully prevented from entering the explosion range of concentration by the addition of an inert gas. This method of inertization is commonly used in industrial plants to keep processes safe. For this purpose, the oxygen concentration in the over-all mixture is often monitored, taking an appropriate safety margin into account. The mixture would not become flammable, independent of the amount of fuel added, while the oxygen content is below the so-called limiting oxygen concentration (LOC). The aim of this paper is to investigate the inertization-related characteristics of the two different inert gases nitrogen (N2) and carbon dioxide (CO2). The LOC of a series of alcohols and ketones was therefore measured. The experimental determination of the LOCs was carried out according to EN 1839 (2017) using the tube method at ambient initial pressure and suitable initial temperature to evaporate the liquid sample. Triangular diagrams, which represent the explosion ranges, were constructed from the results and additional inertization-related parameters derived: the minimum inert gas/air ratio (IAR) and the minimum inert gas/combustible gas ratio (ICR). It is well-known that carbon dioxide exhibits a stronger inerting effect than nitrogen. In agreement, the ratio LOC(CO2)/LOC(N2) was now determined to be a constant value of 1.33 ± 0.04 in the applied temperature range at ambient pressure. In inertization applications, this ratio in future helps to calculate LOC(CO2) from the much more often known LOC(N2).

External morphology of newly-hatched juveniles of Aegla lata (Crustacea, Aeglidae)

ABSTRACT Aegla is a genus of freshwater anomuran Crustacea known for having epimorphic postembryonic development. The newly-hatched juveniles’ morphology have been described for only 11 of the 93 known species. These descriptions are important tools for identifying juveniles and useful characteristics for phylogenetic analyses. This study aims to describe and illustrate the external morphology of the first juvenile stage of Aegla lata. Ovigerous females were collected, fed, and monitored periodically in the laboratory until the eggs hatched. The newly-hatched juveniles were fixed in an alcohol series and preserved in a 70% alcohol and glycerine solution (2:1 ratio) for subsequent dissection and analysis under light microscopy. The appendages were illustrated using a camera lucida and then described. Scanning electron microscopy was used to analyse some specimens, allowing the detailed observation of the setal morphology, some cephalothoracic appendages, and lineae aeglicae. Pappose setae were also observed in the protopod and dactylus of cheliped. The newly-hatched juvenile of A. lata has a set of the following characteristics: basal segment of antennule with serrate setae; distal segment of antennule with pappose setae; merus of second maxilliped with simple setae; and merus of third maxilliped without simple setae.

Hydroxyapatite nanoparticles reinforced polyvinyl alcohol/chitosan blend for optical and energy storage applications

AbstractBiopolymer blend nanocomposite films composed of polyvinyl alcohol (PVA) and chitosan (CS) with varying quantities of hydroxyapatite (HA) nanoparticles were developed using a green solution casting method. The formation of blend nanocomposite was confirmed by Fourier‐transform infrared spectroscopy (FTIR), ultraviolet–visible (UV) spectrometer, field‐emission scanning electron microscopy (FE‐SEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Mechanical parameters such as tensile strength, percentage elongation at break, hardness, dielectric constant, and temperature‐dependent alternating current (AC) conductivity were analyzed. The bonding between the nanoparticles and PVA/CS blend was verified by the shift in distinctive peaks of blend in the nanocomposites to a higher wavenumber in the FTIR spectra. The UV spectra demonstrated the difference in absorbance and transmittance of the PVA/CS blend with the reinforcement of HA nanofillers. The bandgaps of the nanocomposites marginally decreased with an increase in nanoparticle loading. The SEM and XRD patterns revealed the ordered arrangement of the blend matrix due to the presence of nanoparticles. The assessment of thermal characteristics obtained from DSC and TGA demonstrated a clear increase in phase transition temperature and thermal stability of nanocomposites. The electrical conductivity measurement indicated a rise in dielectric constant and AC conductivity of blend nanocomposites with the addition of nanoparticles. The temperature‐dependent AC conductivity showed a reduction in activation energy as temperature and nanoparticle loading increased. The tensile strength and surface hardness of the PVA/CS blend nanocomposite increased with the dosage of HA content in the blend matrix.Highlights A series of polyvinyl alcohol (PVA)/chitosan (CS)/hydroxyapatite (HA) nanocomposites were prepared by the green method Enhanced optical property, thermal stability, and glass transition temperature Possess excellent dielectric constant and alternating current conductivity The inclusion of HA increased the mechanical strength of the PVA/CS blend A potential blend nanocomposite for flexible optoelectronic and charge storage devices.

Lobatozoum woodi n. sp. (Digenea: Didymozoidae) parasitizing Euthynnus alletteratus (Scombriformes: Scombridae) in the coast of the State of Rio de Janeiro, Brazil.

The aim of this study was to describe a new species of Didymozoidae (Trematoda) found in the mesentery of Euthynnus alletteratus (Rafinesque) off Cabo Frio, in the coastal area of the state of Rio de Janeiro, Brazil. Thirty specimens of E. alletteratus were obtained between August 2023 and June 2024, directly from traders who sell fresh fish in markets. The parasites were fixed in AFA (93% ethanol 70%, 5% formaldehyde and 2% glacial acetic acid) with or without compression, stained with Langeron's hydrochloric carmine, dehydrated in an alcohol series, clarified in clove oil and mounted in Canada balsam as permanent slides. The new species was assigned to the genus Lobatozoum Ishii, 1935, mainly by the presence of lobes in the posterior region of the body and by the arrangement of the testes, ovary and vitellaria. Lobatozoum woodi n. sp. differs from all congeneric species mainly by presenting three testicular tubules, by the size of pharynx, larger than the oral sucker, and by the absence of digestive glands cells in esophagus and initial portion of caeca. The finding of a new species of Lobatozoum represents the eleventh valid species in the genus.

Role of hydrodynamic conditions and type of foam stabilizer for antifoam efficiency

The effects of antifoam and surfactant concentration on the foamability of solutions of an anionic (SLES) and nonionic (Brij 35) surfactants and a series of polyvinyl alcohols with 88% and 98% degree of hydrolysis and molecular masses between 31 and 205 kDa, were studied. Three methods which differ in the way of air incorporation were used for foaming – Bartsch test, shake test and Ultra Turrax. Mixed silicone oil-silica particles antifoam was studied. The antifoam was introduced in the foaming solution as pre-dispersed in organic solvent or as antifoam-in-water emulsion. It was shown that the antifoam is very active in the fast foaming methods (Bartsch and shake tests) for the slow adsorbing polymers PVA and has no any activity in the slow foaming method (Ultra Turrax) for the fast adsorbing surfactants with electrostatic stabilization (SLES). The efficiency of pre-dispersed in organic solvent antifoam is much higher as compared to that of emulsified antifoam, due to the faster segregation of the silica particles and silicone oil in the emulsified antifoam. The antifoam efficiency increases with antifoam concentration and with lowering the surfactant concentration. In a given foaming method, the antifoam efficiency is the highest in PVA solutions with 98% DH, intermediate for PVA with 88% DH and Brij 35, and the lowest for SLES solutions. At a certain degree of hydrolysis, the molecular mass of PVA has no significant effect on the antifoam activity. Good correlation between the antifoam efficiency and the stability of the pseudo emulsion film formed between the antifoam globule and the bubble surface is established, showing that the electrostatic repulsion is more efficient to prevent the entering of the antifoam globules on the air-water interface, as compared to the steric repulsion.

Regioselectivity Switch between Enantioselective 1,2- and 1,4-Addition of Allyl Aryl Ketones with 2,3-Dioxopyrrolidines.

A vinylogous addition reaction of allyl aryl ketones with good yields and excellent regioselectivity catalyzed by squaramide catalysts has been developed. A series of chiral tertiary alcohols and bicyclic pyrrolidones could be synthesized in good to excellent yields, enantioselectivities, and diaseteroselectivities. Both experimental results and DFT calculations indicate that 1,2-addition reaction is favorable when the reaction is employed at a lower temperature, while the 1,4-addition/cyclization pathway is favorable when the reaction is employed at a higher temperature. Furthermore, the formation of compound 4 can potentially arise from either the 1,4-addition/cyclization pathway or retro-aldol reaction of compound 3, followed by subsequent 1,4-addition/cyclization.

Photoredox/Enzymatic Catalysis Enabling Redox-Neutral Decarboxylative Asymmetric C-C Coupling for Asymmetric Synthesis of Chiral 1,2-Amino Alcohols.

Photocatalysis offers tremendous opportunities for enzymes to access new functions. Herein, we described a redox-neutral photocatalysis/enzymatic catalysis system for the asymmetric synthesis of chiral 1,2-amino alcohols via decarboxylative radical C-C coupling of N-arylglycines and aldehydes by combining an organic photocatalyst, eosin Y, and carbonyl reductase RasADH. Notably, this protocol avoids using any sacrificial reductants. A possible reaction mechanism proposed is that the transformation proceeds through sequential photoinduced decarboxylative radical addition to an aldehyde and a photoenzymatic deracemization pathway. This redox-neutral photoredox/enzymatic strategy is promising not only for effective synthesis of a series of chiral amino alcohols in a green and sustainable manner but also for the design of other novel C-C radical coupling transformations for the synthesis of bioactive molecules.

Influence of diverse MgClx/R’nClmAly(OR)z activators/supports in tailoring of entangled state of UHMWPE

Heterogeneous MgClx/EtnAly(2-ethyl-1-hexoxide)z dual activator/support, together with bis[N-(3‑tert-butylsalicylidene)pentafluoroanilinato] titanium(IV) dichloride complex, has demonstrated its potential in the synthesis of low entangled UHMWPE under controlled polymerization conditions. The work was corroborated with the solid-state processed uniaxial tapes having ultimate mechanical properties, which were found at par with the polymer synthesized using homogeneous catalysis with the edge to govern nascent polymer morphology. The activator/support is tuned depending on the combination of aluminum-alkyls and alcohols employed in the synthesis. Herein, a series of alcohols (2-ethyl-1-hexanol, 3-methyl-1-butanol, n-butanol, n-pentanol, n-octanol, cyclohexanol, and benzyl alcohol) and phenol are employed in the formation of the MgCl2/ROH adduct followed by reaction with different aluminum-alkyls (TEA, DEAC, TiBAl, and TMA) to form a diverse class of MgClx/R’nClmAly(OR)z activators/supports. The diverse activators are employed in the synthesis of low-entangled UHMWPE, the resultant polymers display controlled fine particle morphology without any reactor fouling/wall sheeting. The characteristics of the synthesized polymers are studied using SEM, DSC, melt rheology, high-temperature NMR, and FT-IR. All the synthesized polymers are found to be linear UHMWPE having a reduced number of entanglement, making them suitable (with exceptions) for solvent-free solid-state processing to produce high-strength and modulus tapes. An attempt is made to illustrate the varying entanglement state by correlating the nascent UHMWPE characteristics (such as particle morphology, particulate density, single crystal lamellae structures, storage modulus build-up, and advanced thermal analysis) with the solid-state processing. The resultant catalytic systems of the type Cat. 1/MgClx/R’nClmAly(OR)z are found to form unique nano dual activator/support, crucial for the supporting of a small number of active sites, thus reducing chain overlap during the polymer synthesis. The developed catalytic systems allow tailoring the molecular weight from 3 to 43 million g/mol and Ð from 3.3 to 38 of the synthesized polymers. The mechanical properties are found to be ∼ 4 N/tex of specific strength and > 200 N/tex of specific modulus.

FRI390 The Effects Of Chronic Asprosin Administration On Ovarian Tissue

Abstract Disclosure: H. Kelestimur: None. Z. Oz: None. M. Ozdede: None. I. Serhatlioglu: None. N. Kaya Tektemur: None. E. Kacar: None. Purpose: Asprosin is a novel glucogenic and orexigenic hormone produced by the fibrillin 1 (FBN1) gene that is secreted by white adipose tissue during fasting. Fibrillins (FBNs) are structural and signalling proteins found mainly in the ovarian stroma, tunica albuginea and theca layers. The aim of this study was to determine the effects of asprosin on ovarian tissue in the female rats. Materials and methods: Twenty-four female Sprague-Dawley rats were randomly divided into 2 groups (n=12) as control and asprosin. Asprosin and control groups were given intraperitoneal saline at doses of 500 ng/kg and 1 ml/kg, respectively, at 14.00 every day for eight weeks. After the application, decapitation was performed, and the rapidly removed ovarian tissues were placed in a 10% formaldehyde solution for fixation. Formalin-fixed ovaries were dehydrated in a graded alcohol series and graded ethanol, respectively After that, all tissues were embedded in paraffin wax. The ovaries were cut into 5-µm sections and stained with hematoxylin and eosin (H&E) and also Masson trichrome staining. Ovarian follicular reserve and fibrosis were evaluated by light microscopy. The follicles were histologically classified as primordial, primary, secondary, and Graaf and all follicular structures were counted in each section. The fibrosis was evaluated with Masson’s trichrome staining and scored from 0 to 3 semi-quantitatively (0 = no fibrosis, 1 = low fibrosis, 2 = intermediate fibrosis, 3 = severe fibrosis). Results: In the asprosin group, unlike the control group, occasional congestion was observed in the vessels located in the ovarian medulla. Apart from this, no histopathological changes were found. An increase in fibrosis was detected in the ovarian sections of the asprosin group when compared to the control group (p = 0,035). In the light microscopic evaluation of the ovarian sections of the rats in the asprosin group, the primary and secondary follicle numbers were significantly higher than those in the control group (p = 0,008 and p = 0,047 respectively). However, the difference between the control and asprosin groups in terms of the primordial follicle, Graafian follicle and corpus luteum numbers were not statistically significant. Conclusion: Our results have shown that chronic asprosin administration causes an increase in the number of primary and secondary follicles, suggesting that changes in ovarian steroidogenesis and folliculogenesis depending on the application may lead to positive effects on female fertility. Keywords: Asprosin, adipokine, ovarian follicle. Acknowledgement: This study was supported by TUBITAK (Project: 220S744). Presentation: Friday, June 16, 2023

Photopyroelectric technique for the measurement of optical properties of pure liquids

Photopyroelectric technique, in the transmission configuration, was shown adequate for the measurement of the optical properties of pure liquids. The analytical scheme involves the scanning of the photopyroelectric signal as a function of the sample thickness. Optical absorption coefficients, at four wavelengths in the near infrared region (904 nm, 980 nm, 1310 nm, and 1550 nm), were measured for eight pure substances, distilled water and glycerol, among them. Strong optical absorption was obtained, particularly for pure liquids with a hydroxyl group in their molecular structure. In order to figure out about the influence of this chemical group on optical properties as function of the size of the molecule, optical absorption coefficient for a series of linear alcohols at 1550 nm was also measured.

Rhodium‐Catalysed Selective C−H Allylation of 1H‐Indazoles with Vinylethylene Carbonate: Easily Introducing Allylic Alcohol

AbstractAn efficient rhodium(III)‐catalysed C−H activation of 3‐aryl‐1‐H‐indazoles with easily available vinylethylene carbonate has been reported. A series of allyl alcohol substituted 3‐aryl‐1‐H‐indazoles were obtained with broad functional groups tolerance and favourable stereoselectivity. Notably, C−H and C−O bonds were selectively activated in “one pot” manner, releasing CO2 as the sole by‐product and avoiding external oxidant. This protocol provides a powerful approach for the post stage C−H allylation of indazole‐based substrates.

1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) Promoted N-Alkylation of Quinazolinones through Nucleophilic Substitution of Benzyl Alcohols.

We describe here a protocol for alkylation of quinazolinones with a series of primary or secondary alcohols under metal-free conditions. A class of quinazolinone derivatives were obtained in 31%-97% yield with good functional group tolerance. This protocol provides chemists a direct and effective way to obtain bioactive quinazolinone derivatives.

Plant-based Biomass/Polyvinyl Alcohol Gels for Flexible Sensors.

Flexible sensors show great application potential in wearable electronics, human-computer interaction, medical health, bionic electronic skin and other fields. Compared with rigid sensors, hydrogel-based devices are more flexible and biocompatible and can easily fit the skin or be implanted into the body, making them more advantageous in the field of flexible electronics. In all designs, polyvinyl alcohol (PVA) series hydrogels exhibit high mechanical strength, excellent sensitivity and fatigue resistance, which make them promising candidates for flexible electronic sensing devices. This paper has reviewed the latest progress of PVA/plant-based biomass hydrogels in the construction of flexible sensor applications. We first briefly introduced representative plant biomass materials, including sodium alginate, phytic acid, starch, cellulose and lignin, and summarized their unique physical and chemical properties. After that, the design principles and performance indicators of hydrogel sensors are highlighted, and representative examples of PVA/plant-based biomass hydrogel applications in wearable electronics are illustrated. Finally, the future research is briefly prospected. We hope it can promote the research of novel green flexible sensors based on PVA/biomass hydrogel.

Preparation and properties of erythritol/exfoliated graphite nanoplatelets @ polyaniline microencapsulated phase change materials with improved photothermal conversion efficiency

Multifunctional microencapsulated phase change materials (MePCMs) with sugar alcohols as core and functional polymers as shell are of great importance for the applications of sugar alcohols as phase change materials (PCMs). However, the preparation of such kinds of MePCMs was restricted due to the water solubility and the high phase change temperature of sugar alcohols. Herein, we proposed a facial method and prepared a series of novel multifunctional sugar alcohols @ polyaniline (PANI) MePCMs with m-erythritol (ME) as core, PANI as shell, and exfoliated graphite nanoplatelets (GNPs) as thermal conductive and photothermal conversion enhancement fillers. The prepared MePCMs were composed of GNPs@ME particles microencapsulated by PANI shell when the loading of GNPs was no more than 4 wt%. Otherwise, the GNPs@ME particles would be wrapped by excessive GNPs at first and then microencapsulated by the PANI shell. The prepared MePCMs exhibited good anti-leakage performance. The latent heat storage capacity of the prepared MePCMs could attain 254.3 J·g−1. The thermal conductivity of the MePCMs with 8 wt% GNPs could be greatly enhanced to 196 % higher than that of the MePCMs without GNPs. Meanwhile, due to the synergetic nucleating effect of PANI and GNPs, the supercooling of ME in the MePCM was effectively suppressed from about 100 °C to about 56 °C with 2 wt% GNPs. The prepared MePCMs also exhibited excellent photothermal conversion performance. Consequently, the results reported here could pave the way for the preparation of sugar alcohol-based multifunctional MePCMs for solar thermal applications and latent heat storage systems.

Electronic Conductance and Thermopower of Cross-Conjugated and Skipped-Conjugated Molecules in Single-Molecule Junctions.

We report a combined experimental and theoretical study of a series of thiomethyl (SMe) anchored cross-conjugated molecules featuring an acyclic central bridging ketone and their analogous skipped-conjugated alcohol derivatives. Studies of these molecules in a gold|single-molecule|gold junction using scanning tunneling microscopy-break junction techniques reveal a similar conductance (G) value for both the cross-conjugated molecules and their skipped-conjugated partners. Theoretical studies based on density functional theory of the molecules in their optimum geometries in the junction reveal the reason for this similarity in conductance, as the predicted conductance for the alcohol series of compounds varies more with the tilt angle. Thermopower measurements reveal a higher Seebeck coefficient (S) for the cross-conjugated ketone molecules relative to the alcohol derivatives, with a particularly high S for the biphenyl derivative 3a (-15.6 μV/K), an increase of threefold compared to its alcohol analog. The predicted behavior of the quantum interference (QI) in this series of cross-conjugated molecules is found to be constructive, though the appearance of a destructive QI feature for 3a is due to the degeneracy of the HOMO orbital and may explain the enhancement of the value of S for this molecule.

Lewis Acid-Mediated Electrophilic Thiolative Difunctionalization of Enimides: Rapid Access to β-Amino Sulfides.

An efficient and practical route for the synthesis of β-amino sulfides by Lewis acid-mediated electrophilic thiolative difunctionalization of enimides is disclosed. A series of free phenols, electron-rich arene, alcohol, azide, and hydride, are successfully incorporated into the substrates in high regio- and stereoselectivities under mild conditions. The obtained products possess multiple functional groups and can be easily transformed to other valuable molecules.

Chromium‐Doped Nickel Oxide and Nickel Nitride Mediate Selective Electrocatalytic Oxidation of Sterol Intermediates Coupled with H2 Evolution

AbstractReplacing the oxygen evolution reaction (OER) with the thermodynamically favorable electrooxidation of organics is considered a promising approach for the simultaneous production of hydrogen (H2) and high‐value chemicals. However, exploring and optimizing efficient electrocatalysts remains a challenge for large‐scale production of value‐added steroid carbonyl and H2. Herein, Cr‐NiO/GF and Cr‐Ni3N/GF (GF: graphite felt) electrocatalysts were designed as anode and cathode for the production of steroid carbonyls and H2, respectively. The cooperative Cr‐NiO and ACT (4‐acetamido‐2,2,6,6‐tetramethyl‐1‐piperidine‐N‐oxyl) electrocatalyst can be extended to the electrooxidation of a series of steroid alcohols to the corresponding aldehydes. Additionally, Cr‐Ni3N displays superior electrocatalytic activity for hydrogen evolution reaction (HER), with a low overpotential of 35 mV to deliver 10 mA cm−2. Furthermore, the system coupled with anodic electrooxidation of sterol and cathodic HER exhibited excellent performance with high space‐time yield of 48.85 kg m−3 h−1 for steroid carbonyl and 1.82 L h−1 for H2 generation in a two‐layer stacked flow cell. Density Functional Theory (DFT) calculations indicated that Cr doping effectively stabilizes ACTH on the NiO surface, and ACTH molecule could be captured via the ketonic oxygen interaction with Cr, resulting in excellent electrocatalytic activity. This work develops a novel approach to the rational design of efficient electrocatalysts for the simultaneous production of H2 and large‐scale value‐added pharmaceutical carbonyl intermediates.

Chromium-Doped Nickel Oxide and Nickel Nitride Mediate Selective Electrocatalytic Oxidation of Sterol Intermediates Coupled with H2 Evolution.

Replacing the OER with the thermodynamically favorable electrooxidation of organics is considered a promising approach for the simultaneous production of H2 and high-value chemicals. However, exploring and optimizing efficient electrocatalystsremains a challenge for large-scale production of high value-added steroid carbonyl and H2. Herein, Cr-NiO/GF and Cr-Ni3N/GF electrocatalysts were designed as anode and cathode for the production of steroid carbonyls and hydrogen, respectively. The cooperative Cr-NiO and ACT (4-acetamido-TEMPO) electrocatalyst can be extended to the electrooxidation of a series of steroid alcohols to the corresponding aldehydes. Additionally, Cr-Ni3N displays superior electrocatalytic activity for HER, with a low overpotential of 35 mV to deliver 10 mA cm-2. Furthermore, the system coupled with anodic electrooxidation of sterol and cathodic HER exhibited excellent performance with high space-time yield of 48.85 kg/(m3·h) for steroid carbonyl and 1.82 L/h for H2 generation in a two-layer stacked flow cell. DFT calculations indicated that Cr doping effectively stabilizes ACT on the NiO surface, and ACTH molecule could be captured via the ketonic oxygen interaction with Cr, resulting in excellent electrocatalytic activity. This work develops a novel approach to the rational design of efficient electrocatalysts for the simultaneous production of H2 and large-scale high added pharmaceutical carbonyl intermediates.

Dependence of Photothermal Rate Enhancements of Urethane Formation upon the Nature of Light Exposure and Solution Viscosity

The photothermal effect of nanoparticles naturally results in nanometer scale heat sources. Despite their highly localized nature, these heat sources can be used to drive bulk scale chemical transformations. However, due to the localization in both time and space, it is reasonable to expect that the time scale of heating, as well as transport of reactive species into and out of the heated volumes during this time, might play a role in determining the efficacy of photothermal heating for driving chemical reactions. Herein, we report an investigation into these effects for the reaction between hexamethylene diisocyanate and a series of alcohols to form urethane bonds. The length of photothermal heating is controlled via the duration of light exposure, using either a modulated continuous wave (2 min duty cycle) or a nanosecond pulse (8 ns pulses) laser that deliver nearly the same total energy to the system. Mass transport is controlled by changing the alcohol from butanol to butanediol to a polyester diol, resulting in reaction mixtures that change their viscosity from 1.66 to 206 cSt. We use infrared spectroscopy to follow the urethane production and associated isocyanate consumption. We then fit the course of the reaction to a kinetic model from which we extract rate constants used to quantify the degree of photothermal rate enhancement. For the chemical systems used, we find no significant dependence on viscosity. We also find that, for the light sources used, the average rate enhancement is not significantly affected by the length of light exposure, but the rate of the reaction during the time of exposure increases with larger instantaneous power.