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Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high‐cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support‐free, excellent chemoselectivity, low‐cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction. [ABSTRACT FROM AUTHOR]

The wet chemical reduction method was used to modify polydopamine (PDA) functionalized oxygenated carbon nitride (O‐g‐C3N4) nanosheets to prepare in situ growth of Cu nanoparticles (Cu NPs) decorated on nanosheets. The PDA attached to the surface of O‐g‐C3N4 provided a uniformly distributed platform for copper nanoparticles. It also provided rich functional groups and provided good conditions for the dispersion of Cu/PDA/O‐g‐C3N4 in pure oil. Through TEM testing, Cu NPs with a diameter of 5–10 nm were evenly distributed on the PDA/O‐g‐C3N4 nanosheets. Through the sliding test on the steel surface, it was obvious that adding 0.2 wt % Cu/PDA/O‐g‐C3N4 to pure oil had a lowest coefficient of friction. In addition, the wear marks on the surface of Cu/PDA/O‐g‐C3N4 steel discs were studied with an optical microscope and a three‐dimensional profiler and its wear resistance was better than Cu NPs, O‐g‐C3N4 and Cu/O‐g‐C3N4. [ABSTRACT FROM AUTHOR]

The splitting of N2 into well‐defined terminal nitride complexes is a key reaction for nitrogen fixation at ambient conditions. In continuation of our previous work on rhenium pincer mediated N2 splitting, nitrogen activation and cleavage upon (electro)chemical reduction of [ReCl2(L2)] {L2 = N(CHCHPtBu2)2–} is reported. The electrochemical characterization of [ReCl2(L2)] and comparison with our previously reported platform [ReCl2(L1)] {L1 = N(CH2CH2PtBu2)2–} provides mechanistic insight to rationalize the dependence of nitride yield on the reductant. Furthermore, the reactivity of N2 derived nitride complex [Re(N)Cl(L2)] with electrophiles is presented. [ABSTRACT FROM AUTHOR]

As a critical part of flexible electronics, flexible circuits inevitably work in a dynamic state, which causes electrical deterioration of brittle conductive materials (i.e., Cu, Ag, ITO). Recently, gallium‐based liquid metal particles (LMPs) with electrical stability and self‐repairing have been studied to replace brittle materials owing to their low modulus and excellent conductivity. However, LMP‐coated Ga2O3 needs to activate by external sintering, which makes it more complicated to fabricate and gives it a larger short‐circuit risk. Core–shell structural particles (Ag@LMPs) that exhibit excellent initial conductivity(8.0 Ω sq−1) without extra sintering are successfully prepared by coating nanosilver on the surface of LMPs through in situ chemical reduction. The critical stress at which rigid Ag shells rupture can be controlled by adjusting the Ag shell thickness so that LM cores with low moduli can release, achieving real‐time self‐repairing (within 200 ms) under external destruction. Furthermore, a flexible circuit utilizing Ag@LMPs is fabricated by screen printing, and exhibits outstanding stability and durability (R/R0 < 1.65 after 10 000 bending cycles in a radius of 0.5 mm) because of the functional core–shell structure. The self‐repairable Ag@LMPs prepared in this study are a candidate filler for flexible circuit design through multiple processing methods. [ABSTRACT FROM AUTHOR]

The reduction stage of chemical looping steam methane reforming was investigated to determine the kinetics of the reduction reaction for CeO2‐Fe2O3 mixed oxides. CeO2, Fe2O3, and CeO2‐Fe2O3 mixed oxides with different molar ratios were prepared by chemical precipitation. Characterization tests indicated the lowest Brunauer‐Emmett‐Teller surface area for samples with higher Fe content. The largest area under reduction peaks during hydrogen temperature‐programmed reduction measurements was also related to the samples with highest Fe content. Reduction of the oxygen carriers with lower Fe content was well represented by a phase boundary‐controlled model. [ABSTRACT FROM AUTHOR]

The study aims to document the effect of starch‐stabilised copper‐based nanoparticles (CuNPs) on the biosynthesis of pharmaceutically valuable secondary metabolites, especially saponins, of the reputed nootropic herb Bacopa monnieri (L.) Pennell. CuNPs were synthesised chemically by the reduction of cupric sulphate pentahydrate with ascorbic acid using starch as the capping agent. They were characterised by UV–visible spectrophotometry, Fourier‐transform infra‐red spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy and zeta potential. The nanoparticles consisted of cuprous oxide and metallic copper, were approximately spherical, polydispersed with diameter <20 nm. Hydroponically grown B. monnieri plants were treated in vivo with the CuNPs between the concentrations of 0–100 mg l−1. Spectrophotometric estimation of the total contents of saponins, alkaloids, phenolics, flavonoids and DPPH radical scavenging capacity from the methanolic extracts of the whole plants showed a hormetic increase in the content of secondary metabolites in a concentration‐dependent manner from 5 mg l−1 until it declined at toxic metabolic concentration. This was accompanied by an increase in ROS markers hydrogen peroxide and malondialdehyde as well as a hormetic effect on activities of phenylalanine ammonia lyase and antioxidant enzymes catalase, ascorbate peroxidase and superoxide dismutase. CuNPs at sub‐toxic concentrations were found to enhance secondary metabolism and antioxidant capacity in Bacopa monnieri through ROS‐mediated defence response. [ABSTRACT FROM AUTHOR]

The Ψ[CH2NH] reduced amide bond is a peptide isostere widely used in the development of bioactive pseudopeptides. Reported here is a method of chemoenzymatic posttranslational modification for the synthesis of Ψ[CH2NH]‐containing peptides converted from ribosomally expressed peptides. The posttranslational conversion composed of an enzymatic cyclodehydration and facile two‐step chemical reduction achieves deoxygenation of a specific amide bond present in a nonprotected peptide in water. This method generates the Ψ[CH2NH] bond in peptides and is applicable to various peptide sequences, potentially enabling the preparation of a library of Ψ[CH2NH]‐containing peptides. [ABSTRACT FROM AUTHOR]

The Ψ[CH2NH] reduced amide bond is a peptide isostere widely used in the development of bioactive pseudopeptides. Reported here is a method of chemoenzymatic posttranslational modification for the synthesis of Ψ[CH2NH]‐containing peptides converted from ribosomally expressed peptides. The posttranslational conversion composed of an enzymatic cyclodehydration and facile two‐step chemical reduction achieves deoxygenation of a specific amide bond present in a nonprotected peptide in water. This method generates the Ψ[CH2NH] bond in peptides and is applicable to various peptide sequences, potentially enabling the preparation of a library of Ψ[CH2NH]‐containing peptides. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction to value‐added chemicals is a critical and challenging process for research of sustainable energy. Herein, we synthesize new nickel single atom catalysts embedded in nitrogen doped hollow carbon spheres (Ni−N/C‐x) via thermal treatment of Ni salts and nitrogen doped hollow carbon spheres (N/C‐x). The state of Ni species on Ni−N/C‐x can be tuned by the nitrogen species of N/C‐x and pyrrolic‐N favors the formation of atomic Ni species. Two catalysts, namely, Ni−N/C‐1/4 contains more pyrrolic‐N and more amount of atomic Ni species than that on Ni−N/C‐3/2 have been prepared. During all the measurement potential range, Ni−N/C‐1/4 displays a much higher catalytic activity for CO2 reduction to CO than Ni−N/C‐3/2. Within the potential range of −0.63 V to −0.98 V versus reversible hydrogen electrode (RHE), the faradaic efficiencies of CO on Ni−N/C‐1/4 exceed 70 %. Furthermore, Ni−N/C‐1/4 exhibits high selectivity for CO and excellent stability during 4.5 h of CO2 reduction electrolysis at the potential of −0.78 V versus RHE. [ABSTRACT FROM AUTHOR]

Non‐spherical Au/Ag nanoparticles can be generated by chemical reduction of silver ions in the presence of preformed gold nanoparticles. The process of particle formation can be controlled by concentrations of ligands and reducing agent. The formation of ellipsoidal, nanorod‐ and peanut‐shaped nanoparticles as well as of more complex fractal nanoassemblies can be explained by changes in particle surface state, electrochemical potential formation and particle‐internal self‐polarization effects. It is possible to create highly fractal nanoassemblies with sizes between the mid‐nanometer and the lower micrometer range. The assemblies are marked by high optical absorption and complex nano‐networks of very high surface‐to‐volume ratios and a granular base structure. [ABSTRACT FROM AUTHOR]

Catalytic CO2 reduction to fuels and chemicals is a major pursuit in reducing greenhouse gas emissions. One approach utilizes the reverse water‐gas shift reaction, followed by Fischer–Tropsch synthesis, and iron is a well‐known candidate for this process. Some attempts have been made to modify and improve its reactivity, but resulted in limited success. Now, using ruthenium–iron oxide colloidal heterodimers, close contact between the two phases promotes the reduction of iron oxide via a proximal hydrogen spillover effect, leading to the formation of ruthenium–iron core–shell structures active for the reaction at significantly lower temperatures than in bare iron catalysts. Furthermore, by engineering the iron oxide shell thickness, a fourfold increase in hydrocarbon yield is achieved compared to the heterodimers. This work shows how rational design of colloidal heterostructures can result in materials with significantly improved catalytic performance in CO2 conversion processes. [ABSTRACT FROM AUTHOR]

Catalytic CO2 reduction to fuels and chemicals is a major pursuit in reducing greenhouse gas emissions. One approach utilizes the reverse water‐gas shift reaction, followed by Fischer–Tropsch synthesis, and iron is a well‐known candidate for this process. Some attempts have been made to modify and improve its reactivity, but resulted in limited success. Now, using ruthenium–iron oxide colloidal heterodimers, close contact between the two phases promotes the reduction of iron oxide via a proximal hydrogen spillover effect, leading to the formation of ruthenium–iron core–shell structures active for the reaction at significantly lower temperatures than in bare iron catalysts. Furthermore, by engineering the iron oxide shell thickness, a fourfold increase in hydrocarbon yield is achieved compared to the heterodimers. This work shows how rational design of colloidal heterostructures can result in materials with significantly improved catalytic performance in CO2 conversion processes. [ABSTRACT FROM AUTHOR]

One‐electron reduction of corannulene, C20H10, with Li metal in diglyme resulted in crystallization of [{Li+(diglyme)2}4(C20H10.−)2(C20H10‐C20H10)2−] (1), as revealed by single‐crystal X‐ray diffraction. This hybrid product contains two corannulene monoanion‐radicals along with a dianionic dimer, crystallized with four Li+ ions wrapped by diglyme molecules. The dimeric (C20H10‐C20H10)2− anion provides the first crystallographically confirmed example of spontaneous radical dimerization for C20H10.−. The C−C bond length between the two C20H10.− bowls of 1.588(5) Å is consistent with the single σ‐bond character of the linker. The trans‐disposition of two bowls in the centrosymmetric (C20H10‐C20H10)2− dimer is observed with the torsion angle around the central C−C bond of 180°. Comprehensive theoretical analysis of formation/decomposition processes of the dimeric dianion has been carried out in order to evaluate the nature of bonding and energetics of the C20H10.− coupling. It is found that such σ‐bonded dimers are thermodynamically unstable due to large preparation energy and repulsive Pauli component of the bonding, but kinetically persistent due to a high energy barrier provided by the existing spin‐crossing point. [ABSTRACT FROM AUTHOR]

The design and synthesis of uranium sorbent materials with high uptake efficiency, capacity and selectivity, as well as excellent hydrolytic stability and radiation resistance remains a challenge. Herein, a polyoxometalate (POM)–organic framework material (SCU‐19) with a rare inclined polycatenation structure was designed, synthesized through a solvothermal method, and tested for uranium separation. Under dark conditions, SCU‐19 can efficiently capture uranium through ligand complexation using its exposed oxo atoms and partial chemical reduction from UVI to UIV by the low‐valent Mo atoms in the POM. An additional UVI photocatalytic reduction mechanism can occur under visible light irradiation, leading to a higher uranium removal without saturation and faster sorption kinetics. SCU‐19 is the only uranium sorbent material with three distinct sorption mechanisms, as further demonstrated by X‐ray photoelectron spectroscopy (XPS) and X‐ray absorption near edge structure (XANES) analysis. [ABSTRACT FROM AUTHOR]

The design and synthesis of uranium sorbent materials with high uptake efficiency, capacity and selectivity, as well as excellent hydrolytic stability and radiation resistance remains a challenge. Herein, a polyoxometalate (POM)–organic framework material (SCU‐19) with a rare inclined polycatenation structure was designed, synthesized through a solvothermal method, and tested for uranium separation. Under dark conditions, SCU‐19 can efficiently capture uranium through ligand complexation using its exposed oxo atoms and partial chemical reduction from UVI to UIV by the low‐valent Mo atoms in the POM. An additional UVI photocatalytic reduction mechanism can occur under visible light irradiation, leading to a higher uranium removal without saturation and faster sorption kinetics. SCU‐19 is the only uranium sorbent material with three distinct sorption mechanisms, as further demonstrated by X‐ray photoelectron spectroscopy (XPS) and X‐ray absorption near edge structure (XANES) analysis. [ABSTRACT FROM AUTHOR]

The design and synthesis of uranium sorbent materials with high uptake efficiency, capacity and selectivity, as well as excellent hydrolytic stability and radiation resistance remains a challenge. Herein, a polyoxometalate (POM)–organic framework material (SCU‐19) with a rare inclined polycatenation structure was designed, synthesized through a solvothermal method, and tested for uranium separation. Under dark conditions, SCU‐19 can efficiently capture uranium through ligand complexation using its exposed oxo atoms and partial chemical reduction from UVI to UIV by the low‐valent Mo atoms in the POM. An additional UVI photocatalytic reduction mechanism can occur under visible light irradiation, leading to a higher uranium removal without saturation and faster sorption kinetics. SCU‐19 is the only uranium sorbent material with three distinct sorption mechanisms, as further demonstrated by X‐ray photoelectron spectroscopy (XPS) and X‐ray absorption near edge structure (XANES) analysis. [ABSTRACT FROM AUTHOR]

Designing green and efficient photocatalysts for pollutant degradation is of great significance, where the photogenerated charge separation plays an important role in improving the photocatalytic efficiency. A three‐dimensional popcorn‐like TiO2 mesoporous sphere with tunable Pt contents has been successfully synthesized by a combination of hydrothermal process and chemical reduction. The resultant Pt/TiO2 mesoporous spheres exhibit a suppressed charge recombination due to the synergic effect of TiO2 and Pt. To be specific, the Pt nanoparticle on the TiO2 facilitates the collection and transfer of the photogenerated electrons originated from the mesoporous TiO2. Density functional theory (DFT) calculated results further confirm the faster carries separation in Pt/TiO2. Meanwhile, the specific three‐dimensional structure endows Pt/TiO2 spheres with enhanced light scattering ability, a high surface area, and porous structure. As a consequence, the novel Pt/TiO2 mesoporous spheres present multiple fold enhancement on the RhB photodegradation efficiency compared with that of neat TiO2, in which 1.0% Pt/TiO2 presents the highest photocatalytic activity. This work proposes a new perspective of green and efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Chemical reduction of OBO‐fused double[5]helicene with Group 1 metals (Na and K) has been investigated for the first time. Two doubly‐reduced products have been isolated and structurally characterized by single‐crystal X‐ray diffraction, revealing a solvent‐separated ion triplet (SSIT) with Na+ ions and a contact‐ion pair (CIP) with K+ ion. As the key structural outcome, the X‐ray crystallographic analysis discloses the consequences of adding two electrons to the double helicene core in the SSIT without metal binding and reveals the preferential binding site in the CIP with K+ counterions. In both products, an increase in the twisting of the double helicene core upon charging was observed. The negative charge localization at the central core has been identified by theoretical calculations, which are in full agreement with X‐ray crystallographic and NMR spectroscopic results. Notably, it was confirmed that the two‐electron reduction of OBO‐fused double[5]helicene is reversible. [ABSTRACT FROM AUTHOR]

Chemical reduction of OBO‐fused double[5]helicene with Group 1 metals (Na and K) has been investigated for the first time. Two doubly‐reduced products have been isolated and structurally characterized by single‐crystal X‐ray diffraction, revealing a solvent‐separated ion triplet (SSIT) with Na+ ions and a contact‐ion pair (CIP) with K+ ion. As the key structural outcome, the X‐ray crystallographic analysis discloses the consequences of adding two electrons to the double helicene core in the SSIT without metal binding and reveals the preferential binding site in the CIP with K+ counterions. In both products, an increase in the twisting of the double helicene core upon charging was observed. The negative charge localization at the central core has been identified by theoretical calculations, which are in full agreement with X‐ray crystallographic and NMR spectroscopic results. Notably, it was confirmed that the two‐electron reduction of OBO‐fused double[5]helicene is reversible. [ABSTRACT FROM AUTHOR]

Fine nanoparticles of CuO, generated in‐situ by the chemical reduction method, were immobilized on cucurbit[6]uril support to afford nanocomposite CuO@CB[6] as an air‐stable green powder. The nanocomposite was fully characterized by various physicochemical techniques, such as FTIR, PXRD, XPS, FESEM, EDX, Elemental mapping, HRTEM, TGA, and ICP‐AES. It has been found to be an efficient heterogeneous nanocatalyst for the synthesis of a series of 2H‐indazoles from aldehyde, amine, and azide, under base‐ and ligand‐free conditions, at a low concentration of the metal (0.2 mole %). The augmented catalytic activity of the CuO NPs is attributed to the fine size of the nanoparticles. The nanocatalyst was retrieved from the reaction mixture by simple filtration and reused up to five times with insignificant deprivation in its catalytic activity. All synthesized 2H‐indazoles were isolated in good to excellent yield (55‐96%) and characterized by 1H and 13C NMR studies. Three new indazoles are additionally characterized by DEPT 135 spectroscopy and HRMS spectra. [ABSTRACT FROM AUTHOR]

Understanding photodriven multielectron reaction pathways requires the identification and spectroscopic characterization of intermediates and their excited‐state dynamics, which is very challenging due to their short lifetimes. To the best of our knowledge, this manuscript reports for the first time on in situ spectroelectrochemistry as an alternative approach to study the excited‐state properties of reactive intermediates of photocatalytic cycles. UV/Vis, resonance‐Raman, and transient‐absorption spectroscopy have been employed to characterize the catalytically competent intermediate [(tbbpy)2RuII(tpphz)RhICp*] of [(tbbpy)2Ru(tpphz)Rh(Cp*)Cl]Cl(PF6)2 (Ru(tpphz)RhCp*), a photocatalyst for the hydrogenation of nicotinamide (NAD‐analogue) and proton reduction, generated by electrochemical and chemical reduction. Electronic transitions shifting electron density from the activated catalytic center to the bridging tpphz ligand significantly reduce the catalytic activity upon visible‐light irradiation. [ABSTRACT FROM AUTHOR]

Understanding photodriven multielectron reaction pathways requires the identification and spectroscopic characterization of intermediates and their excited‐state dynamics, which is very challenging due to their short lifetimes. To the best of our knowledge, this manuscript reports for the first time on in situ spectroelectrochemistry as an alternative approach to study the excited‐state properties of reactive intermediates of photocatalytic cycles. UV/Vis, resonance‐Raman, and transient‐absorption spectroscopy have been employed to characterize the catalytically competent intermediate [(tbbpy)2RuII(tpphz)RhICp*] of [(tbbpy)2Ru(tpphz)Rh(Cp*)Cl]Cl(PF6)2 (Ru(tpphz)RhCp*), a photocatalyst for the hydrogenation of nicotinamide (NAD‐analogue) and proton reduction, generated by electrochemical and chemical reduction. Electronic transitions shifting electron density from the activated catalytic center to the bridging tpphz ligand significantly reduce the catalytic activity upon visible‐light irradiation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Consumer preference today is for the consumption of functional food and the reduction of chemical preservatives. Moreover, the antimicrobial properties and health‐promoting qualities of plant secondary metabolites are well known. Due to forecasted climate changes and increasing human population, agricultural practices for saving water have become a concern. In the present study, the physiological responses of curly kale Brassica oleracea L. convar. Acephala (DC) var. sabellica to drought stress and the impact of water limitation on the concentration of selected secondary metabolites were investigated under laboratory‐controlled conditions. RESULTS: Results indicated that drought stress increased the content of trans‐2‐hexenal, phytol and δ‐tocopherol, and decreased chlorophyll content. Moreover, drought stress increased antioxidant capacity and the expression of AOP2, a gene associated with the biosynthesis of aliphatic alkenyl glucosinolates, and of three genes – TGG1, TGGE and PEN2 – encoding for myrosinases, the enzymes involved in glucosinolate breakdown. CONCLUSION: The present study shows that water limitation during the growing phase might be exploited as a sustainable practice for producing curly kale with a high concentration of nutritionally important health‐promoting bioactive metabolites. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Mono‐ and dianions of 2‐tert‐butyl‐3a2‐azapentabenzo[bc,ef,hi,kl,no]corannulene (1 a) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na+(18‐crown‐6)(THF)2}3{Na+(18‐crown‐6)(THF)}(1 a2−)2], revealed the presence of a naked dianion. In contrast, controlled reaction of 1 a with Cs allowed the isolation of singly and doubly reduced forms of 1 a, both forming π‐complexes with cesium ions in the solid state. In [{Cs+(18‐crown‐6)}(1 a−)]⋅THF, asymmetric binding of the Cs+ ion to the concave surface of 1 a− is observed, whereas in [{Cs+(18‐crown‐6)}2(1 a2−)], two Cs+ ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules. [ABSTRACT FROM AUTHOR]

Mono‐ and dianions of 2‐tert‐butyl‐3a2‐azapentabenzo[bc,ef,hi,kl,no]corannulene (1 a) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na+(18‐crown‐6)(THF)2}3{Na+(18‐crown‐6)(THF)}(1 a2−)2], revealed the presence of a naked dianion. In contrast, controlled reaction of 1 a with Cs allowed the isolation of singly and doubly reduced forms of 1 a, both forming π‐complexes with cesium ions in the solid state. In [{Cs+(18‐crown‐6)}(1 a−)]⋅THF, asymmetric binding of the Cs+ ion to the concave surface of 1 a− is observed, whereas in [{Cs+(18‐crown‐6)}2(1 a2−)], two Cs+ ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules. [ABSTRACT FROM AUTHOR]

Fragrance and flavor industries could not imagine business without aldehydes. Processes for their commercial production raise environmental and ecological concerns. The chemical reduction of organic acids to aldehydes is challenging. To fulfill the demand of a mild and selective reduction of carboxylic acids to aldehydes, carboxylic acid reductases (CARs) are gaining importance. We identified two new subtype IV fungal CARs from Dichomitus squalens CAR (DsCAR) and Trametes versicolor CAR (Tv2CAR) in addition to literature known Trametes versicolor CAR (TvCAR). Expression levels were improved by the co‐expression of GroEL‐GroES with either the trigger factor or the DnaJ‐DnaK‐GrpE system. Investigation of the substrate scope of the three enzymes revealed overlapping substrate‐specificities. Tv2CAR and DsCAR showed a preferred pH range of 7.0 to 8.0 in bicine buffer. TvCAR showed highest activity at pH 6.5 to 7.5 in MES buffer and slightly reduced activity at pH 6.0 or 8.0. TvCAR appeared to tolerate a wider pH range without significant loss of activity. Type IV fungal CARs optimal temperature was in the range of 25–35 °C. TvCAR showed a melting temperature (Tm) of 55 °C indicating higher stability compared to type III and the other type IV fungal CARs (Tm 51–52 °C). Finally, TvCAR was used as the key enzyme for the bioreduction of 3,4‐dihydroxyphenylacetic acid to the antioxidant 3‐hydroxytyrosol (3‐HT) and gave 58 mM of 3‐HT after 24 h, which correlates to a productivity of 0.37 g L−1 h−1. [ABSTRACT FROM AUTHOR]

Benzene centered tris‐alkylimidazolium bromide salts, denoted as BTIm(R)3Br3 ; where R=C12H25 and C14H29 have been prepared and structurally characterised. The hydrogelation ability and stabilizer role of these salts for the synthesis of silver nanoparticles (AgNPs) via chemical reduction method is described. A worth note that the BTIm(C12)3Br3 compound could lead a thermoreversible fibrous‐hydrogel in water, which plays a dual role as stabilizer and directing agent for silver dendritic nanostructures. While the partial‐hydrogel of BTIm(C12)3Br3 contributes silver nanospheres. The non‐gel solutions of BTIm(C12)3Br3 in dichloromethane, and BTIm(C14)3Br3 in water as stabilizers did not show control over the shape of AgNPs, and they lead mixed morphology. The experimental conditions, i. e. temperature, heating‐cooling process and the physical state of the stabilizer play a key role in the thermoreversible hydrogel and partial‐hydrogel control over the morphology of Ag nanostructures. Overall, the outcome of the present study provides new possibility for the use of thermoreversible fibrous gels to prepare Ag dendrites. [ABSTRACT FROM AUTHOR]

The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(TrenTIPS)(OCP)] (TrenTIPS=N(CH2CH2NSiPri3)3) with KC8/2,2,2‐cryptand gives [{U(TrenTIPS)}2{μ‐η2(OP):η2(CP)‐OCP}][K(2,2,2‐cryptand)]. The coordination mode of this trapped 2‐phosphaethynolate is unique, and derives from an unprecedented highly reduced and highly bent form of this ligand with the most acute P‐C‐O angle in any complex to date (P‐C‐O ∡ ≈127°). The characterisation data support a mixed‐valence diuranium(III/IV) formulation, where backbonding from uranium gives a highly reduced form of the P‐C‐O unit that is perhaps best described as a uranium‐stabilised OCP2−. radical dianion. Quantum chemical calculations reveal that this gives unprecedented carbene character to the P‐C‐O unit, which engages in a weak donor–acceptor interaction with one of the uranium ions. [ABSTRACT FROM AUTHOR]

The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(TrenTIPS)(OCP)] (TrenTIPS=N(CH2CH2NSiPri3)3) with KC8/2,2,2‐cryptand gives [{U(TrenTIPS)}2{μ‐η2(OP):η2(CP)‐OCP}][K(2,2,2‐cryptand)]. The coordination mode of this trapped 2‐phosphaethynolate is unique, and derives from an unprecedented highly reduced and highly bent form of this ligand with the most acute P‐C‐O angle in any complex to date (P‐C‐O ∡ ≈127°). The characterisation data support a mixed‐valence diuranium(III/IV) formulation, where backbonding from uranium gives a highly reduced form of the P‐C‐O unit that is perhaps best described as a uranium‐stabilised OCP2−. radical dianion. Quantum chemical calculations reveal that this gives unprecedented carbene character to the P‐C‐O unit, which engages in a weak donor–acceptor interaction with one of the uranium ions. [ABSTRACT FROM AUTHOR]

Differently shaped nickel crystals were obtained at ambient temperature via simple liquid chemical reduction by adding different surfactants (such as polyvinylpyrrolidone (PVP) or cetyltrimethylammonium bromide (CTAB)), with hydrazine hydrate as reducing agent and ethanol as solvent. Nickel nanoparticles (NPs), thorny nickel nanowires or rose‐like nickel crystals were obtained in the synthesis process without any surfactant, with PVP or with CTAB, respectively. The corresponding ruthenium‐on‐Ni crystal supported catalysts (Ru/Ni) were synthesized through galvanic replacement. Their catalytic behavior was tested in the model reaction of the hydrogenation of benzene. The order of their catalytic activity was Ru/thorny Ni nanowire > Ru/rose‐like Ni > Ru/Ni NPs due to different shapes and structures of Ru/Ni. The Ru/thorny Ni nanowires catalyst also exhibited outstanding stability for benzene hydrogenation to cyclohexane. The as‐obtained Ni and Ru/Ni samples were characterized by X‐ray diffraction (XRD), scanning electronic microscopy (SEM), SEM energy dispersive X‐ray spectroscopy (SEM‐EDS), high‐sensitivity low‐energy ion scattering spectroscopy (HS‐LEIS), X‐ray photoelectron spectroscopy (XPS), SEM‐EDS elemental mapping, transmission electron micro‐scope (TEM), and high resolution TEM (HRTEM), to reveal their morphologies, structures and element distribution and further illustrate the intrinsic reasons for their different performance in catalyzing benzene hydrogenation. [ABSTRACT FROM AUTHOR]

Front Cover: A Tetrapodal Penta-Carbene Ligand and Iron(III) Complex (Eur. J. Inorg. Keywords: Carbene ligands; Iron; Magnetic properties; Structure elucidation; Tetrapodal pentadentate complexes EN Carbene ligands Iron Magnetic properties Structure elucidation Tetrapodal pentadentate complexes 1 1 1 07/18/23 20230713 NES 230713 B The Front Cover b shows selected tetrapodal-pentadentate "butterflies" taking flight. Carbene ligands, Iron, Magnetic properties, Structure elucidation, Tetrapodal pentadentate complexes. [Extracted from the article]

A novel and highly efficient dual‐targeting platform was designed to ensure targeted in vivo delivery of dual‐action PtIV prodrugs. The dual targeting was established by liposomal encapsulation of PtIV complexes, thereby utilizing the enhanced permeability and retention (EPR) effect as the first stage of targeting to attain a high accumulation of the drug‐loaded liposomes in the tumor. After the release of the PtIV prodrug inside cancer cells, a second stage of targeting directed a portion of the PtIV prodrugs to the mitochondria. Upon intracellular reduction, these PtIV prodrugs released two bioactive molecules, acting both on the mitochondrial and on the nuclear DNA. Our PtIV system showed excellent activity in vitro and in vivo, characterized by a cytotoxicity in a low micromolar range and complete tumor remission, respectively. Notably, marked in vivo activity was accompanied by reduced kidney toxicity, highlighting the unique therapeutic potential of our novel dual‐targeting dual‐action platform. [ABSTRACT FROM AUTHOR]

Using a reductive sidewall functionalization concept, we prepared for the first time a covalent inter‐carbon‐allotrope hybrid consisting of single‐walled carbon nanotubes (SWCNTs) and the endohedral fullerene Sc3N@C80. The new compound type was characterized through a variety of techniques including absorption spectroscopy, Raman spectroscopy, TG‐MS, TG‐GC‐MS, and MALDI‐TOF MS. HRTEM investigations were carried out to visualize this highly integrated architecture. [ABSTRACT FROM AUTHOR]

A 1:1 complex of a 2,6‐bis‐tetrazinylpyridine pincer ligand, btzp, with ZnCl2 is characterized. The molecule is shown to be redox active by cyclic voltammetry and by chemical reduction. The resulting monoanion loses chloride to yield a radical species [Zn(btzp)Cl] whose EPR spectrum is observed. DFT studies show that the electron added upon reduction goes into an orbital primarily comprised of tetrazine nitrogen pπ character. The Zn–Cl bonds lengthen but the Zn–Ntz bonds shorten upon reduction, in response to taking on amide character. In an alternative approach to evaluating the electron accepting capacity of btzp, the molecule [Ru(btzp)Cl2(CO)] has been fully characterized and shows a CO stretching frequency 84 cm–1 higher than that of its terpyridine analog. This result indicates btzp is strongly electron withdrawing; the CO stretching frequency for [Ru(btzp)Cl2(CO)] is among the highest ever observed for a ruthenium(II) monocarbonyl complex. Computational experiments on [Ru(btzp)Cl2(L)] test the influence of L on π‐back donation to btzp. [ABSTRACT FROM AUTHOR]

Metal catalysts have been used extensively in addressing energy and environmental issues. A reduction process is often needed to activate these catalysts. However, there is a lack of techniques to accurately control this process, thus the chemical composition of the catalysts is usually unclear. Ni‐based catalysts are among the most commonly used due to their effectiveness and low costs. In this work, we use the reduction of a Ni/Al2O3 catalyst used in dry reforming of methane to demonstrate a novel technique that well controls the reduction extent of metal catalysts. We achieve this goal by using IR spectroscopy to monitor and quantify the reduction product, H2O, in the process. Specifically, we measure a full and a partial H2O production kinetics, and subsequently develop an algorithm to control the reduction extent of the Ni catalyst in a wide range. This algorithm is proved effective. The technique can be applied generally to any pretreatment process that involves IR measurable gases and its wide application would greatly promote the fundamental catalyst structure‐performance investigation. [ABSTRACT FROM AUTHOR]

Iron mediated catalytic reactions are of great interest in the field of organic synthesis because they are economic and naturally abundant. However, the use of iron catalyst in the field of free radical cyclization or reduction of alkyl halides remains limited. Here we describe the use of an unprecedented combination of iron and zinc in the reduction and 5‐exo‐trig radical cyclization of alkyl halides under mild condition in the absence of added ligands or additives. The method is distinguished by its wide scope, functional group tolerance and the use of 1,4‐cyclohexadiene as the source of hydrogen, which aids easy purification. [ABSTRACT FROM AUTHOR]

2H‐Azirines are useful precursors for the synthesis of a variety of chiral aziridine and amine derivatives with a range of biological activities. Owing to the ring strain and the presence of a C=N double bond, 2H‐azirines are more reactive than other types of ketimine, and undergo a range of enantioselective reactions, including reduction and Diels–Alder reactions, as well as nucleophilic addition to the C=N double bond. Therefore, the enantioselective reactions of 2H‐azirines has become a hot topic, in particular within the last few years. In this Minireview, we focus on the enantioselective reactions of 2H‐azirines by using catalytic or stoichiometric amounts of chiral additives, the reaction mechanisms, and the applications of these reactions of 2H‐azirines and related compounds in organic synthesis. [ABSTRACT FROM AUTHOR]

Ti(C,N)‐based cermets were prepared by in situ carbothermal reduction in TiO2 and subsequent liquid phase sintering under vacuum. The prepared cermets were examined using XRD, SEM, TEM, and EDX. During solid‐state sintering, fine TiC particles were formed through the carbothermal reduction in TiO2. A great number of (Ti,W,Mo)C complete solid solutions containing more W and Mo subsequently formed through the counter diffusion of the fine TiC and carbides. The majority of the coarse TiN particles in the raw powders remained undissolved. During liquid phase sintering, Ti‐based carbonitride complex solid solutions with less W or Mo precipitated on the coarse TiN particles and fine (Ti,W,Mo)C particles, resulting in black core/gray rim structures and white core/gray rim structures, respectively. Moreover, small amounts of Ti‐based carbonitride complex solid solutions precipitated directly from the liquid binder phase in some areas enriched in W and Mo during the cooling stage after sintering, resulting in coreless grains. Ultimately, after being sintered at 1400°C for 1 hour, the present cermets were characterized with white core/gray rim grains, black core/gray rim grains and a few gray grains. In addition, the interfaces between the black core/gray rim grains and binder phase were atomically smooth, exhibiting a (200)R//(111¯)B orientation relationship with a perfect coherency state. [ABSTRACT FROM AUTHOR]

Metal‐catalyzed cross coupling reactions are efficient synthetic methods and developing continuously for the synthesis of diverse range of heterocycles, found in wide range of natural products. Among others, reductive Heck reaction has elegantly been employed to access various natural products. This review article covers the updated summary of relevant literature on the application of reductive Heck reaction for the synthesis of natural products. Discussion on the underlying mechanistic rationale has also been included wherever felt necessary. [ABSTRACT FROM AUTHOR]

Metallurgical synthesis of solar grade silicon (SoG−Si) is an existing challenge due to the strict chemical composition of silicon for solar cells. Here, we report a green and facile approach to synthesize high‐purity silicon (99.98 wt%, 0.12 ppmw B and 0.18 ppmw P) for solar cells by the carbothermic reduction of SiC with SiO2 in a vacuum graphite resistance furnace. Catalyst of Fe2O3 plays the role of reducing the concentration of CO(g), lowering the energy consumption and improving the purity and yield of silicon. The present work is one‐step to obtain silicon with less B and P, but it is composed of silicon synthesis, oxidation refining, vacuum refining and blowing refining, which discloses an innovative chemical concepts of in‐situ synthesis combined with refining. According to the characterizations of the reacted SiC particles performed by XRD, Raman, PL, XPS, SEM and TEM, the morphologies and formation mechanisms of the in‐situ silicon from the horizons of atomic scale were revealed for the first time. It was evidenced conclusively that the Si−C bonding is broken from the (006) planes of 6H‐SiC at 1850°C by the reaction of SiC(s) + 2SiO2(l)=3SiO(g) + CO(g), and then the silicon nucleates on the (101) planes of 6H‐SiC and grows along the [111] direction at 1950°C via the vapor‐solid reaction of SiO(g) + SiC(s)=2Si(l) + CO(g). [ABSTRACT FROM AUTHOR]

Here, the reduction chemistry of mono‐ and binuclear α‐diimine‐Re(CO)3 complexes with proton responsive ligands and their application in the electrochemically‐driven CO2 reduction catalysis are presented. The work was aimed to investigate the impact of 1) two metal ions in close proximity and 2) an internal proton source on catalysis. Therefore, three different Re complexes, a binuclear one with a central phenol unit, 3, and two mononuclear, one having a central phenol unit, 1, and one with a methoxy unit, 2, were utilised. All complexes are active in the CO2‐to‐CO conversion and CO is always the major product. The catalytic rate constant kcat for all three complexes is much higher and the overpotential is lower in DMF/water mixtures than in pure DMF (DMF=N,N‐dimethylformamide). Cyclic voltammetry (CV) studies in the absence of substrate revealed that this is due to an accelerated chloride ion loss after initial reduction in DMF/water mixtures in comparison to pure DMF. Chloride ion loss is necessary for subsequent CO2 binding and this step is around ten times faster in the presence of water [2: kCl(DMF)≈1.7 s−1; kCl(DMF/H2O)≈20 s−1]. The binuclear complex 3 with a proton responsive phenol unit is more active than the mononuclear complexes. In the presence of water, the observed rate constant kobs for 3 is four times higher than of 2, in the absence of water even ten times. Thus, the two metal centres are beneficial for catalysis. Lastly, the investigation showed that the phenol unit has no impact on the rate of the catalysis, it even slows down the CO2‐to‐CO conversion. This is due to an unproductive, competitive side reaction: After initial reduction, 1 and 3 loose either Cl− or undergo a reductive OH deprotonation forming a phenolate unit. The phenolate could bind to the metal centre blocking the sixth coordination site for CO2 activation. In DMF, O−H bond breaking and Cl− ion loss have similar rate constants [1: kCl(DMF)≈2 s−1, kOH≈1.5 s−1], in water/DMF Cl− loss is much faster. Thus, the effect on the catalytic rate is more pronounced in DMF. However, the acidic protons lower the overpotential of the catalysis by about 150 mV. Two is better than one! The impact of two metal centres and of a proton source in a α‐diimine Re(CO)3‐catalyst on the electrochemical CO2‐to‐CO conversion has been investigated. [ABSTRACT FROM AUTHOR]

Noble metal assisted catalytic activity is a renounced adopted strategy since long times. Herein, we report an arresting of silver nanoparticles onto solid surface resin matrix in order to perform catalytic activity taking by 4‐nitrophenol as a model feed agent. The surface decoration has been evidenced by electron microscopy techniques. The superiority of this resin‐confined Ag nanoparticle based catalyst lies in their fast reduction and wide range of working temperature. The thermodynamic parameters related to activation energy, temperature dependency, and reusability can make this a suitable 'easy to install' all‐solid‐state fabricated catalytic membrane device. A facile approach of altering surface chemistry of a polymeric resin to attain diversification in physico‐chemical properties was developed. This study spotlighted on modification of pyrogallol resin using nanoparticles to fabricate organic‐inorganic nanocomposites which can establish a new era in the field of heterogeneous catalytic applications. we reported the behavior of metal‐resin nanocomposite towards catalytic reduction of 4‐nitrophenol at room temperature and at higher temperatures.The catalytic reduction reaction has very much important as hazardous pollutant converted into non‐toxic significant product. [ABSTRACT FROM AUTHOR]

Herein, we describe an intermolecular direct branched‐selective α‐alkylation of cyclic ketones with simple alkenes as the alkylation agents. Through an enamine‐transition metal cooperative catalysis mode, the α‐alkylation is realized in an atom‐ and step‐economic manner with excellent branched selectivity for preparing β‐branched ketones. Employment of a pair of bulky Brønsted acid and base as additives is responsible for enhanced efficiency. Promising enantioselectivity (74 % ee) has been obtained. Experimental and computational mechanistic studies suggest that a pathway through alkene migratory insertion into the Ir−C bond followed by C−H reductive elimination is involved for the high branched selectivity. [ABSTRACT FROM AUTHOR]

Incorporating atomically dispersed metal species into functionalized metal–organic frameworks (MOFs) can integrate their respective merits for catalysis. A cage‐controlled encapsulation and reduction strategy is used to fabricate single Ru atoms and triatomic Ru3 clusters anchored on ZIF‐8 (Ru1@ZIF‐8, Ru3@ZIF‐8). The highly efficient and selective catalysis for semi‐hydrogenation of alkyne is observed. The excellent activity derives from high atom‐efficiency of atomically dispersed Ru active sites and hydrogen enrichment by the ZIF‐8 shell. Meanwhile, ZIF‐8 shell serves as a novel molecular sieve for olefins to achieve absolute regioselectivity of catalyzing terminal alkynes but not internal alkynes. Moreover, the size‐dependent performance between Ru3@ZIF‐8 and Ru1@ZIF‐8 is detected in experiment and understood by quantum‐chemical calculations, demonstrating a new and promising approach to optimize catalysts by controlling the number of atoms. [ABSTRACT FROM AUTHOR]

Nanocrystalline molybdenum disilicide (MoSi2) is synthesized in a specially designed autoclave at 900°C. The XRD results revealed that the formation of MoSi2 is favorable with the blend of MoO3, Si, and Mg powders. The HR‐TEM and SAED patterns confirm the formation of MoSi2 phase. The structural parameters (crystallite size, strain, stress, and deformation energy density) are calculated using the Williamson‐Hall (W‐H) analysis. The formation mechanism involved in the synthesis of MoSi2 is proposed. The nonisothermal oxidation kinetics (~1200°C) of MoSi2 phase is examined through the thermal analysis techniques. The activation energy is determined by the Kissinger‐Akahira‐Sunsose isoconversional kinetic model. Finally, the reaction mechanism involved during the oxidation of MoSi2 phase is identified using the integral master‐plots method. Formation mechanism and non‐isothermal oxidation kinetics of molybdenum disilicide (MoSi2). [ABSTRACT FROM AUTHOR]

Uranium tetraboride (UB4) was successfully synthesized by boro/carbothermal reduction of UO2 with B4C and carbon as combined reduction agents under flowing argon. The effects of processing temperature and mole ratios of starting materials on phase evolution were studied. XRD results demonstrated that UB4 was obtained with 3.75 mol% B4C in excess based on the UO2/B4C/C molar ratios of 1:1:1 at 1500°C. SEM observation revealed that submicrometer‐sized quasi‐spherical UB4 particles cemented together to be an aggregate. The laser particle size analysis showed that the particle size was in the range of 1‐10 μm. The oxidation behavior of UB4 was also investigated by TG and XRD. The oxidation of UB4 started at about 500°C and it showed better oxidation resistance than other basic uranium nuclear fuels (UO2, UC, UN and U3Si2). The oxidation chemical process of UB4 was presented as a three‐step process: (a) the formation of U3O8 and B2O3 oxidation products; (b) the formation of UB2O6 intermediate product by the interaction of U3O8 and B2O3; (c) the decomposition of UB2O6 to get U3O8. [ABSTRACT FROM AUTHOR]

The effect of the welding GMAW, with heat input of 1.4 kJ/mm, on the microstructure and corrosion resistance of the steel UNS S32304 prior cold worked (0, 10, 30, and 30% thickness reduction) was evaluated. The welding process generated, in the weld joint, the regions: fusion zone (FZ), heat‐affected zone (HAZ), an annealed region around the HAZ, and the metal base zone (BM) deformed by cold working. Excessive ferritization and high precipitation of chromium nitrides in the HAZ were identified. The corrosion resistance of the welded joints was not significantly changed for low deformation levels by cold work (up to 30% thickness reduction). However, for 50% thickness reduction a decrease in the corrosion resistance of the welded joint was observed. The annealing of the BM around the HAZ increased its corrosion resistance, making this region immune to localized corrosion. The heat input used in this study promoted higher ferritization and precipitation of chromium nitrides, lower annealing of the base metal near the HAZ and lower corrosion resistance when compared with the higher heat input used in our previous work (about 2.5 kJ/mm). The effect of the welding GMAW with heat input of 1.4 kJ/mm on the microstructure and corrosion resistance of the steel UNS S32304 prior cold worked was evaluated. The heat input used in this study promoted higher ferritization and precipitation of chromium nitrides, lower annealing of the base metal near the ZTA and lower corrosion resistance when compared with the higher heat input used in previous work (about 2.5 kJ/mm). [ABSTRACT FROM AUTHOR]

Smart polymers are advanced materials that continue to attract scientific community. In this work, self‐healing waterborne polyurethane/reduced graphene oxide (SHWPU/rGO) nanocomposites were prepared by in situ chemical reduction of graphene oxide in a waterborne polyurethane matrix. The chemical structure, morphology, thermal stability, mechanical property, and electrical conductivity of the SHWPU/rGO nanocomposites were characterized. The prepared SHWPU/rGO nanocomposites were further treated under heating, microwave radiating, and electrifying conditions to investigate their healing property. The results showed that chemical reduction of graphene oxide was achieved using hydrazine hydrate as a reducing agent and the rGO was well dispersed in the SHWPU matrix. The thermal stability and mechanical properties of SHWPU/rGO nanocomposites were significantly increased. The SHWPU/rGO nanocomposites can be healed via different methods including heating, microwave radiating, and electrifying. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 202–209 Self‐healing waterborne polyurethane/reduced graphene oxide (SHWPU/rGO) nanocomposites were prepared by in situ reducing graphene oxide in waterborne polyurethane dispersions. The reduced graphene oxide dispersed well in the waterborne polyurethane matrix, and the SHWPU/rGO nanocomposites can be healed using multiple techniques, such as heating, microwave radiating, electrifying, and so forth. [ABSTRACT FROM AUTHOR]

The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C−N coupling. Our methodology has proven to be scalable, air and moisture tolerant, highly chemoselective and engages both aliphatic and aromatic nitro compounds. Moreover, this general and step‐economical synthesis of aromatic secondary amines showcases orthogonality to other aromatic amine syntheses as it tolerates aryl halides and carbonyl compounds. [ABSTRACT FROM AUTHOR]

The chemical reduction of a [3]cumulene ([3]TrTol) has been explored using alkali metals. Mono‐ and doubly reduced forms of [3]TrTol were isolated as solvent‐separated ion pairs with {Na(18‐crown‐6)THF2}+ and {K(18‐crown‐6)THF2}+ counterions and crystallographically characterized. This allowed analysis of structural parameters of the "naked" anions of [3]TrTol without interference from metal binding. The dianion of [3]TrTol was also isolated as a contact‐ion complex with {Cs(18‐crown‐6)}+ cations, thereby adding the effect of metal coordination to the core. Structural comparisons of anions to the neutral molecule, [3]TrTol, outline monotonic increases in bond‐length alternation (BLA) upon stepwise reduction. The greatest BLA value is found for the contact‐ion complex, which shows an alternating sequence of short and long carbon–carbon bonds, consistent with the structure of an alkyne. In contrast to studies on tetraphenyl[3]cumulene, the cumulenic framework of [3]TrTol remains planar in all the derivatives. [ABSTRACT FROM AUTHOR]