Minor Products Research Articles

Interface Engineered V-Zn Hybrids: Electrocatalytic and Photocatalytic CO2 Reductions.

V-Zn hybrids have widely been used as catalyst materials in the environment and as energy. Herein, V-Zn hybrid electrodes were prepared by the hydrothermal and sputter-deposition methods using a Zn foil support. Their electrocatalytic CO2 reduction (EC CO2 RR) performances were tested under various applied potentials, different electrolytes, and concentrations before and after thermal treatment of the demonstrated electrode. Gas and liquid products were confirmed by gas chromatography and nuclear magnetic resonance spectroscopy, respectively. For V-Zn electrode by hydrothermal method produced mainly syngas (CO and H2) with tunable ratio by varying applied potential. Minor products include CH4, C2H4, and C2H6. A liquid product of formate showed a Faradaic efficiency (FE) of 2%. EC CO2 RR efficiency for CO, CH4, and formate was best in 0.2 M KHCO3 electrolyte condition. CO and formate were further increased by photoirradiation and Nafion-treated electrode. Formate and CH4 productions were significantly increased by thermal treatment of the V-Zn electrode. CO production was diminished for the V-Zn electrode by sputter deposition but was recovered by thermal treatment. Photocatalytic CO2 RR was tested to find that RR products include CH3OH, CO, CH4, C2H4, and C2H6. Interestingly long-chain hydrocarbons (CnH2n and CnH2n+2, where n = 3–6) were first observed under mild conditions. The long-chain formation was understood by Fisher-Tropsch (F-T) synthesis. Alkenes were observed to be more produced than alkanes unlike in the conventional F-T synthesis. The present new findings provide useful clues for the development of hybrid electro-and photo-catalysts tested under various experimental conditions in energy and environment.

Functional Characterization of Drosophila melanogaster CYP6A8 Fatty Acid Hydroxylase.

Genomic analysis indicated that the genome of Drosophila melanogaster contains more than 80 cytochrome P450 genes. To date, the enzymatic activity of these P450s has not been extensively studied. Here, the biochemical properties of CYP6A8 were characterized. CYP6A8 was cloned into the pCW vector, and its recombinant enzyme was expressed in Escherichia coli and purified using Ni2+-nitrilotriacetate affinity chromatography. Its expression level was approximately 130 nmol per liter of culture. Purified CYP6A8 exhibited a low-spin state in the absolute spectra of the ferric forms. Binding titration analysis indicated that lauric acid and capric acid produced type І spectral changes, with Kd values 28 ± 4 and 144 ± 20 μM, respectively. Ultra-performance liquid chromatography-mass spectrometry analysis showed that the oxidation reaction of lauric acid produced (ω-1)-hydroxylated lauric acid as a major product and ω-hydroxy-lauric acid as a minor product. Steady-state kinetic analysis of lauric acid hydroxylation yielded a kcat value of 0.038 ± 0.002 min-1 and a Km value of 10 ± 2 μM. In addition, capric acid hydroxylation of CYP6A8 yielded kinetic parameters with a kcat value of 0.135 ± 0.007 min-1 and a Km value of 21 ± 4 μM. Because of the importance of various lipids as carbon sources, the metabolic analysis of fatty acids using CYP6A8 in this study can provide an understanding of the biochemical roles of P450 enzymes in many insects, including Drosophila melanogaster.

Electrochemical CO2 reduction over Pb electrodes modified with group 10, 11, and 14 elements

Surface modification method is a good strategy of improving electrocatalyst performance in CO2 reduction. Herein, lead (Pb) electrode was modified with groups 10 (Ni, Pd, and Pt), 11 (Cu, Ag, and Au), and 14 (Si, Ge, and Sn) elements, and their electrochemical CO2 reduction performances were tested under various conditions of applied potentials, electrolytes, and light irradiation conditions. Major products were observed to be formate and hydrogen and their Faradaic efficiencies were competitive reached to 71% and 28%, respectively. When H2 was increased formate was inversely decreased. Minor products of CO, acetone, and CH4 were mainly dependent on applied potentials and overlayer metals. Overlayer Pt, Pd, and Au metals were relatively stable on the Pb surface during amperometry while others were unstable on the surface. Pb surfaces were observed to be reconstructed during CO2 reduction into nanosheets, nanoplates, nanorods, and nanoislands depending on the applied potentials and overlayer metals. Overall, the present study provides very useful information on the development of Pb-based electrocatalysts for CO2 recycling by electrochemical CO2 reduction.

Two new macropolyhedral chalcogenaboranes: S2B16H18 and SeB16H18

The dithiaborane S2B16H18 (1) is a minor product isolated from the preparation of S2B17H17. It is structurally closely related both to the known compound iso-S2B16H16 (3) and to the new macropolyhedral selenaborarane SeB16H18 (2), which is isolated from the thermal decomposition of the [SeB18H19]− anion. Both new compounds 1 and 2 are therefore produced by boron loss from higher chalcogenaborane compounds. The single-crystal X-ray structures and the boron-11 NMR shielding characteristics show the close similarities of all three compounds.

Exploring the Electrochemistry of Iron Dithiolene and Its Potential for Electrochemical Homogeneous Carbon Dioxide Reduction.

In this work, the dithiolene complex iron(III) bis‐maleonitriledithiolene [Fe(mnt)2] is characterised and evaluated as a homogeneous CO2 reduction catalyst. Electrochemically the Fe(mnt)2 is reduced twice to the trianionic Fe(mnt)2 3− state, which is correspondingly found to be active towards CO2. Interestingly, the first reduction event appears to comprise overlapping reversible couples, attributed to the presence of both a dimeric and monomeric form of the dithiolene complex. In acetonitrile Fe(mnt)2 demonstrates a catalytic response to CO2 yielding typical two‐electron reduction products: H2, CO and CHOOH. The product distribution and yield were governed by the proton source. Operating with H2O as the proton source gave only H2 and CO as products, whereas using 2,2,2‐trifluoroethanol gave 38 % CHOOH faradaic efficiency with H2 and CO as minor products.

CO2 Conversion on N-Doped Carbon Catalysts via Thermo- and Electrocatalysis: Role of C-NO x Moieties.

N-doped carbon (N–C) materials are increasingly popular in different electrochemical and catalytic applications. Due to the structural and stoichiometric diversity of these materials, however, the role of different functional moieties is still controversial. We have synthesized a set of N–C catalysts, with identical morphologies (∼27 nm pore size). By systematically changing the precursors, we have varied the amount and chemical nature of N-functions on the catalyst surface. The CO2 reduction (CO2R) properties of these catalysts were tested in both electrochemical (EC) and thermal catalytic (TC) experiments (i.e., CO2 + H2 reaction). CO was the major CO2R product in all cases, while CH4 appeared as a minor product. Importantly, the CO2R activity changed with the chemical composition, and the activity trend was similar in the EC and TC scenarios. The activity was correlated with the amount of different N-functions, and a correlation was found for the −NOx species. Interestingly, the amount of this species decreased radically during EC CO2R, which was coupled with the performance decrease. The observations were rationalized by the adsorption/desorption properties of the samples, while theoretical insights indicated a similarity between the EC and TC paths.

Solid waste management for the eco-efficiency assessment of energy recovery from waste in incinerators

This study examines energy recovery, specifically electricity generation, from waste in incineration plants. This study decomposes the incinerator system into waste treatment process and energy generation process via a two-stage network structure. We build a Russell multi-activity network data envelopment analysis (RMNDEA) model considering the weak disposability technology, and measure productivity changes over time and assess the plants’ returns-to-scale. We validate the model with an empirical study of 23 incinerators operating between 2011 and 2020 in Taiwan. Our finding that the waste treatment process itself is the major cause of inefficiency indicates that incinerator operators should reallocate input resources. Throughout the study period, there are minor productivity changes and most plants maintain constant returns-to-scale. However, some incinerators in Southern Taiwan having inefficient scale sizes should be rescaled for productivity improvement. The results validate the need to conduct routine eco-efficiency evaluations of solid waste management (SWM) in incinerators.

Preparation of α-MoO3 from H3PMo12O40 precursor: synthesis of 1,2-cyclohexanediol from cyclohexene over α-MoO3-TiO2 catalyst

A series of α-MoO3-TiO2 mixed oxides were prepared by calcining a mixture of the heteropolyacid H3PMo12O40 and TiO2 at temperatures ranging from 350 °C to 600 °C. The mixed oxides thus prepared were characterized and tested for the oxidation of cyclohexene by the oxidizing mixture H2O2/CO2. FTIR and XRD characterizations showed that the Keggin structure of H3PMo12O40 was preserved for calcination temperatures below 400 °C. Above 450 °C, Keggin’s structure collapses. XRD analysis revealed that as the calcination temperature increased, more orthorhombic α-MoO3 was formed. Analysis of the reaction mixture by GC-MS showed that oxidation by the H2O2/CO2 mixture leads to 1,2-cyclohexanediol as the main product and to 2-cyclohexene-1-one and 2-cyclohexene-1-ol as minor products. Oxidation by H2O2/CO2 mixture proved to be more effective than H2O2 alone and CO2 alone. The conversion (69.4%) and the 1,2-cyclohexanediol selectivity (93.2%) obtained over α-MoO3-TiO2 mixed oxides, higher than that obtained with TiO2 monoxide and α-MoO3 monoxide, suggest a synergistic effect between TiO2 and α-MoO3. This efficient and stable catalyst after reuse can be developed for the synthesis of diols.

Towards Sustainable Agricultural Development for Edible Beans in China: Evidence from 848 Households

Minor beans other than soybeans or peanuts are edible beans (EBs) that significantly contribute to the Chinese agricultural sector and play a vital role in the sustainability of agricultural production, diversification of food consumption, and income generation for producers. These beans are an important source of protein in a healthy diet, helping to improve national food security. In addition, adjusting and optimizing the industrial structure promotes the sustainable development of agriculture and diversifies staple food crops and introduction of new revenue streams for EB products. The current study examines the responses of mung bean and broad bean producers to environmental and internal input constraints. This study uses the production function with a multilevel mixed-effects method and is based on 848 households from two major EB-producing provinces of China in 2018 and 2019. The results show that local climatic conditions influence planting behavior. These types of beans are considered as a supplement and backup crop to the staple crop. Commercialization encourages cultivation. Producers show variable price responses to output prices, but very strong responses to product costs. Minor bean production is favored by small households because of its low labor intensity. For households growing these beans for consumption, soil fertility and environmental outcomes are improved. Findings from research on planting behavior have strong policy implications for guiding research and development for drought and pest resistance, market monitoring for price stabilization, promoting EB production through low-cost technologies, and encouraging sustainable agriculture.

Direct Phenylation of nido-B10H14.

As a preliminary step toward its condensation into the porous polymer Activated Borane, the thermolysis of nido-B10H14 (1) in benzene at 200 °C results in the generation of a number of phenylated borane molecular species. The principal product is the new monophenylated compound 5-Ph-nido-B10H13 (2), isolated in 48% yield (based on consumption of 1) and structurally characterized by single-crystal X-ray diffraction analysis, NMR, and mass spectrometry along with other minor products, such as 6-Ph-nido-B10H13 (3), for which we observe UV-light-driven conversion into 2 via a "vertex-flip" mechanism, and novel diphenylated 5,8-Ph2-nido-B10H12 (4). Together, the phenylated derivatives provide a valuable insight into the assembly of Activated Borane and ultimately inform on its structure. The new compounds also display strong blue fluorescence in both solid-state and in solution and are the first examples of the direct phenylation of nido-B10H14, thus opening the door to the straight-forward synthesis of highly luminescent organic-borane hybrid systems.

Notework: Victorian Literature and Nonlinear Style. Simon Reader. Stanford, CA: Stanford University Press, 2021. Pp. vii+238.

<i>Notework: Victorian Literature and Nonlinear Style</i>. Simon Reader. Stanford, CA: Stanford University Press, 2021. Pp. vii+238.

(Invited) N-Doped Carbon Catalysts in Carbon-Dioxide Electroreduction: Effect of the Chemical Composition and Morphology

N-doped carbon (N-C) materials are increasingly popular in different electrochemical and catalytic applications. Due to the structural and stoichiometric diversity of these materials, the role of different functional moieties is still controversial. We have synthesized a set of N-C catalysts, with identical morphology (~27 nm pore size). By systematically changing the precursors, we have varied the amount and chemical nature of N-functions on the catalyst surface. The CO2 reduction (CO2R) properties of these catalysts were tested in electrochemical experiments, where CO was the major product in all cases, while CH4 appeared as minor product. Importantly, the CO2R activity changed with the chemical composition. The activity was correlated with the amount of different N-functions, and correlation was found only for the -NOx species. Interestingly, the amount of this species decreased radically during CO2R, which was coupled with the performance decrease. The observations were rationalized by the adsorption/desorption properties of the samples.In the second part of my presentation I will shed light on the importance of catalyst morphology, using N–C catalysts as a model system. We found that CO2R activity, selectivity, and stability of N–C electrodes are highly dependent on their porosity. The presence of mesopores was demonstrated to be beneficial in achieving high CO selectivity and current density, with an optimal pore size around 27 nm. Even after convoluting factors other than morphology (e.g., surface chemistry, level of graphitization, surface area), the reasons behind the observed trends are complex. CO2 adsorption properties, wetting characteristics, and geometric effects are jointly responsible for the massive difference in the CO2R performance. All these properties must be taken into consideration when we aim to understand the reduction mechanism on different catalysts and while improving the performance further to a technologically relevant level (as alternatives to precious metal catalysts).

Structural analysis of heteropolymetallic complexes: A chiral pinwheel {Cr[Ni(N2S2)]3}3+ and the {trans-(MeCN)Cr(NO)[Ni(N2S2)]2}2+ basket

The [Cr(NO)(MeCN)5]2+ synthon reacts with the Ni(N2S2) metallodithiolate ligand to yield co-crystallized products from which crystals suitable for SC-XRD could be extracted. The major product, {trans-(MeCN)Cr(NO)[Ni(N2S2)]2}2+, abbreviated [Cr(NO)Ni2]2+, is a symmetrical butterfly with upswept Ni(N2S2) wings flanking the trans-Cr(NO)(MeCN) backbone and designated {Cr(NO)}5 in Enemark-Feltham notation (Feltham and Enemark, 1981). The minor product, {Cr[Ni(N2S2)]3}3+, abbreviated [CrNi3]3+, is a pinwheel-type structure analogous to [RhNi3]3+, and both are comparable to tris-bipyridyl analogues.

Curtius-Type Rearrangement of Sulfinyl Azides: A Matrix Isolation and Computational Study.

The highly unstable methyl sulfinyl azide, CH3S(O)N3, has been synthesized and characterized for the first time. In the gas phase, CH3S(O)N3 decomposes quickly at room temperature (300 K) with an estimated half-life (t1/2) of 7 min. Upon irradiation at 266 nm in cryogenic Ar (10 K) and Ne (3 K) matrices, the azide extrudes molecular nitrogen by yielding the novel sulfinyl nitrene intermediate CH3S(O)N in the closed-shell singlet ground state, which has been characterized with matrix-isolation IR and UV-vis spectroscopy. Prolonged irradiation at 266 nm causes Curtius rearrangement of the nitrene to form N-sulfinylamine CH3NSO and S-nitrosothiol CH3SNO. By high-vacuum flash pyrolysis (HVFP) at 800 K, CH3S(O)N3 also decomposes and furnishes CH3S(O)N with minor fragmentation products HNSO and CH2 in the gas phase. A similar photo-induced Curtius-type rearrangement of trifluoromethyl sulfinyl azide CF3S(O)N3 to CF3NSO and CF3SNO has also been observed in matrices. According to the theoretical calculations at the CCSD(T)/aug-cc-pVTZ//B3LYP/6-311++G (3df,3pd) level of theory, the rearrangement of CH3S(O)N3 prefers a stepwise pathway by initial formation of the nitrene intermediate CH3S(O)N. In line with the thermal persistence of CH3S(O)N in the gas phase, the barriers for its subsequent rearrangement are higher than 30 kcal mol-1.

Crystal Growth from Anhydrous HF Solutions of M2+ (M = Ca, Sr, Ba) and [AuF6]-, Not Only Simple M(AuF6)2 Salts.

Crystal growth from anhydrous HF solutions of M2+ (M = Ca, Sr, Ba) and [AuF6]− (molar ratio 1:2) gave [Ca(HF)2](AuF6)2, [Sr(HF)](AuF6)2, and Ba[Ba(HF)]6(AuF6)14. [Ca(HF)2](AuF6)2 exhibits a layered structure in which [Ca(HF)2]2+ cations are connected by AuF6 units, while the crystal structure of Ba[Ba(HF)]6(AuF6)14 exhibits a complex three-dimensional (3-D) network consisting of Ba2+ and [Ba(HF)2]2+ cations bridged by AuF6 groups. These results indicate that the previously reported M(AuF6)2 (M = Ca, Sr, Ba) compounds, prepared in the anhydrous HF, do not in fact correspond to this chemical formula. When the initial M2+/[AuF6]− ratio was 1:1, single crystals of [M(HF)](H3F4)(AuF6) were grown for M = Sr. The crystal structure consists of a 3-D framework formed by [Sr(HF)]2+ cations associated with [AuF6]− and [H3F4]− anions. The latter exhibits a Z-shaped conformation, which has not been observed before. Single crystals of M(BF4)(AuF6) (M = Sr, Ba) were grown when a small amount of BF3 was present during crystallization. Sr(BF4)(AuF6) crystallizes in two modifications. A high-temperature α-phase (293 K) crystallized in an orthorhombic unit cell, and a low-temperature β-phase (150 K) crystallized in a monoclinic unit cell. For Ba(BF4)(AuF6), only an orthorhombic modification was observed in the range 80–230 K. An attempt to grow crystals of Ca(BF4)(AuF6) failed. Instead, crystals of [Ca(HF)](BF4)2 were grown and the crystal structure was determined. During prolonged crystallization of [AuF]6– salts, moisture can penetrate through the walls of the crystallization vessel. This can lead to partial reduction of Au(V) to A(III) and the formation of [AuF4]− byproducts, as shown by the single-crystal growth of [Ba(HF)]4(AuF4)(AuF6)7. Its crystal structure consists of [Ba(HF)]2+ cations connected by AuF6 octahedra and square-planar AuF4 units. The crystal structure of the minor product [O2]2[Sr(HF)]5[AuF6]12·HF was also determined.

Applications of Innovative Non-Thermal Pulsed Electric Field Technology in Developing Safer and Healthier Fruit Juices.

The deactivation of degrading and pectinolytic enzymes is crucial in the fruit juice industry. In commercial fruit juice production, a variety of approaches are applied to inactivate degradative enzymes. One of the most extensively utilized traditional procedures for improving the general acceptability of juice is thermal heat treatment. The utilization of a non-thermal pulsed electric field (PEF) as a promising technology for retaining the fresh-like qualities of juice by efficiently inactivating enzymes and bacteria will be discussed in this review. Induced structural alteration provides for energy savings, reduced raw material waste, and the development of new products. PEF alters the α-helix conformation and changes the active site of enzymes. Furthermore, PEF-treated juices restore enzymatic activity during storage due to either partial enzyme inactivation or the presence of PEF-resistant isozymes. The increase in activity sites caused by structural changes causes the enzymes to be hyperactivated. PEF pretreatments or their combination with other nonthermal techniques improve enzyme activation. For endogenous enzyme inactivation, a clean-label hurdle technology based on PEF and mild temperature could be utilized instead of harsh heat treatments. Furthermore, by substituting or combining conventional pasteurization with PEF technology for improved preservation of both fruit and vegetable juices, PEF technology has enormous economic potential. PEF treatment has advantages not only in terms of product quality but also in terms of manufacturing. Extending the shelf life simplifies production planning and broadens the product range significantly. Supermarkets can be served from the warehouse by increasing storage stability. As storage stability improves, set-up and cleaning durations decrease, and flexibility increases, with only minor product adjustments required throughout the manufacturing process.

Midazolam as a Probe for Heterotropic Drug-Drug Interactions Mediated by CYP3A4.

Human cytochrome P450 CYP3A4 is involved in the processing of more than 35% of current pharmaceuticals and therefore is responsible for multiple drug-drug interactions (DDI). In order to develop a method for the detection and prediction of the possible involvement of new drug candidates in CYP3A4-mediated DDI, we evaluated the application of midazolam (MDZ) as a probe substrate. MDZ is hydroxylated by CYP3A4 in two positions: 1-hydroxy MDZ formed at lower substrate concentrations, and up to 35% of 4-hydroxy MDZ at high concentrations. The ratio of the formation rates of these two products (the site of metabolism ratio, SOM) was used as a measure of allosteric heterotropic interactions caused by effector molecules using CYP3A4 incorporated in lipid nanodiscs. The extent of the changes in the SOM in the presence of effectors is determined by chemical structure and is concentration-dependent. MD simulations of CYP3A4 in the lipid bilayer suggest that experimental results can be explained by the movement of the F-F’ loop and concomitant changes in the shape and volume of the substrate-binding pocket. As a result of PGS binding at the allosteric site, several residues directly contacting MDZ move away from the substrate molecule, enabling the repositioning of the latter for minor product formation.

Significance of Non-Timber Forest Produces with a Special Reference to Banana Plant in the Animistic Religious Practices: A Micro Study on the Karbis in Karbi Anglong, Assam

Every culture irrespective of its simplicity and complexity has its own concept of religious belief and practices. The Karbis are the early settlers of Karbi Anglong district, Assam. Most of them are animistic regarding their religious belief and practices in daily livelihood. The present study examined the use of minor forest products in religious practices of the Karbis. It discussed the significance of NTFPs, with a special reference to the banana plant, as used in a number of their rituals. The data were collected through empirical fieldwork by applying appropriate anthropological research methods. It has been found that different forest resources are immensely important in the cultural and religious practices of the studied people. In this regard, different NTFPs and banana plants are inseparable in such rituals and cultural traditions.

The Radiation Chemistry of NH3···CO Complex in Cryogenic Media as Studied by Matrix Isolation.

The NH3···CO complex can be considered an important building block for cold synthetic astrochemistry leading to the formation of complex organic molecules, including key prebiotic species. In this work, we have studied the radiation-induced transformations of this complex in Ar, Kr, and Xe matrices using FTIR spectroscopy. On the basis of comparison with the quantum chemical calculations at the CCSD(T)/L2a_3 level of theory, it was found that the initial complex had the configuration with hydrogen bonding through the carbon atom of CO. Irradiation of the matrix isolated complex with X-rays at 6 K leads to the formation of a number of synthetic products, namely, HNCO (in all matrices), formamide NH2CHO, NH2CO, and HNCO-H2 (in argon and krypton). The matrix effect on the product distribution was explained by the involvement of different excited states of the complex in their formation. It was suggested that formamide results from the singlet excited states while other species mainly originate from triplet excited states. The latter states are efficiently populated through ion-electron recombination (in all matrices) and through intersystem crossing (particularly, in xenon). High yield of the recombination triplet states is a feature of the processes induced by high-energy radiation (in contrast to direct photolysis). NCO, CN, and NO were found as minor secondary products at high adsorbed doses. The astrochemical implications of the obtained results are discussed.

One‐Pot Sequential [3+2] Cycloaddition and Ring‐Expansion Reaction for Selective Synthesis of Polycyclic Spirooxindole

AbstractThe one‐pot three‐component reaction of L‐proline, isatins and 1‐(2‐hydroxyphenyl)‐3‐phenylprop‐2‐en‐1‐ones and sequential reaction with methyl propiolate in refluxing methanol resulted in novel functionalized spiro[chromane‐2,3′‐indoline]‐2′,4‐diones as major products and spiro[chromeno[3,2‐d]azocine‐2,3′‐indolin]‐3‐ yl)acrylate as minor products. On the other hand, the similar one‐pot‐three‐component reaction of L‐proline, isatins and 3‐(2‐hydroxyphenyl)‐1‐phenylprop‐2‐en‐1‐ones and sequential reaction with methyl propiolate in refluxing acetonitrile predominately afforded the unique 6b,14‐(epoxy[1,2]benzeno)pyrrolo[1′,2′:1,2]azocino[4,5‐c]quinoline‐8‐carboxylates in satisfactory yields.