Significant progress has been made in recent years in the development of liquid metal alloy catalysts. This article provides an overview of the state-of-the-art research pertaining to liquid metal alloy catalysis, including alloy synthesis, reactor design, and theoretical calculations. Different alloy synthesis methods are discussed with a focus on strategies that can achieve colloidal intermetallic structures in liquid metal alloys. Current reactors for liquid metal-based electrocatalytic and thermochemical processes are summarized. The application of theoretical tools, such as machine learning and computational chemistry to further liquid metal alloy design, is discussed. Finally, an outlook on the technological challenges and our perspective on future research opportunities for liquid metal alloy catalysis is presented.
Efficiency and development of guanidine chelate catalysts for rapid and green synthesis of 7‐amino‐4,5‐dihydro‐tetrazolo[1,5‐a]pyrimidine‐6‐carbonitrile derivatives supported by density functional theory (DFT) studies
![Efficiency and development of guanidine chelate catalysts for rapid and green synthesis of 7-amino-4,5-dihydro-tetrazolo[1,5-a]pyrimidine-6-carbonitrile derivatives supported by density functional theory (DFT) studies](https://onlinelibrary.wiley.com/cms/asset/8f280e4d-e2b1-42f1-b7b8-7cb492191211/aoc7262-toc-0001-m.png)
This study was done into these chelate catalytic performances for the environmentally friendly synthesis of 7-amino-4.5-dihydro-tetrazolo[1.5-a]pyrimidine-6-carbonitrile derivatives utilizing aromatic aldehyde, malononitrile, and 5 aminotetrazole as reactants.
Three GUBZCu, GUBZVO, and GUBZPd chelates have been prepared from 2-guanidino benzimidazole (GUBZ ligand) by a bidentate coordinating approach. FT-IR, mass, and NMR spectra; magnetic moment; CHN analysis; UV–Vis spectra; molar conductance; and TGA were studied to describe and estimate the molecular formulae of tested molecules. The stability constant for GUBZ complexes was estimated in the solution. Also, the pH profile displays the extra stability of tested complexes. Structure elucidation of the studied complexes had been supported by density functional theory (DFT) along with calculated electronic and vibrational spectra. Electronic absorption spectra were estimated practically through UV–Vis spectra and theoretically performed using the time-dependent TD-DFT/B3LYP, for computing the absorption maximum, oscillator strength, and excitation energy of the tested compounds. This study was done into these chelates' catalytic performances for the environmentally friendly synthesis of 7-amino-4,5-dihydro-tetrazolo[1,5-a]pyrimidine-6-carbonitrile derivatives utilizing aromatic aldehyde, malononitrile, and 5-amino tetrazole as reactants. The used reactions have been directed in a concerned environment through a green solvent. The obtained results verified the promising catalytic activity and selectivity of the tested complexes. All tested reaction conditions have been enhanced between variable Lewis acid catalysts in associating to our studied complexes. GUBZPd catalyst presented an advantage in overall tests through high yield, green conditions, and short time. Also, the regaining of hetero-catalyst has prospered as well as recycled through the same effectiveness up to four or five times, and then the performance has been reduced. The mechanism of action has been recommended depending on the capability of the Pd (II) complex for totaling extra bonds above the z-axis as well as reinforced with theoretical study. This strategy's simplicity, safety, commercially accessible catalyst, stability, fast reaction time, and outstanding yields may be used in the industry in the future.
Multifunctional alkali‐modified biochar‐nPd/Fe composites for enhanced removal of 2,4‐D: Preparation, characterization, and mechanism
In this study, nPd/Fes were dispersed on peanut shells-derived alkali-modified biochar (BCalk) to obtain BCalk-nPd/Fe composite for overcoming the instability, agglomeration, and oxidation of nPd/Fes. Results demonstrated that the dispersion stability and thermal stability of nPd/Fes were improved and the surface passivation layer was thinned by nanoparticles loading onto the alkalized biochar. Characterization analyses revealed of the improved 2,4-D dichlorination by BCalk-nPd/Fe. After biochar alkalization, more Si-O-Si sites on BCalk responsible for supporting nZVI particles were formed and coupled with nZVI to generate Si-O-Fe. Hence, nPd/Fes were immobilized on BCalk, while the increased oxygen-containing surface functional groups promoted electron transport between nPd/Fes and 2,4-D. Therefore, the BCalk-nPd/Fe exhibited higher dechlorination efficiency toward 2,4-D than that of nPd/Fe and BCraw-nPd/Fe. About 99.25% and 89.11% of the 2,4-D removal and dechlorination, respectively, were achieved after 150 min. Kinetic studies revealed that the removal of 2,4-D using nPd/Fe, BCraw-nPd/Fe, and BCalk-nPd/Fe fitted well in the Langmuir–Hinshelwood kinetic model, and the order of rate constants was as follows: BCalk-nPd/Fe > BCraw-nPd/Fe > nPd/Fe. This study suggested that the prepared composites promoted detoxification and harmlessness of 2,4-D contaminated wastewater and exhibited promising prospect in the efficient treatment of wastewater containing chlorinated organics.
Surface Activated Pyrolytic Carbon Black: A Dual Functional Sustainable Filler for Natural Rubber Composites
The significant rise in end-of-life tires (ELTs) globally poses immediate environmental and human health risks. Therefore, to promote ELTs recycling and to reduce tire industry carbon emissions, herein we present a facile approach for fine-tuning the interfacial interactions between pyrolytic carbon black (P-CB) obtained from ELTs and natural rubber (NR) using phosphonium-based ionic liquid (PIL). The reinforcing effect of PIL-activated P-CB was studied by replacing the furnace-grade carbon black (N330-CB) with varying PIL and P-CB loadings. Adding PIL improved the filler dispersion and the cross-linking kinetics with a substantially reduced zinc oxide loading. Considering the cross-linking and viscoelastic properties, it was concluded that the composite, P-CB/N330-CB-PIL (1.5) + ZnO (1) with half substitution of N330-CB with P-CB synergistically works with 1.5 phr PIL and 1 phr of ZnO resulting in improved dynamic-mechanical properties with a minimal loss tangent at 60 °C (tanδ = 0.0689) and improved glass transition temperature (Tg = - 38 °C) compared to control composite. The significant drop (~ 29 % lower) in tanδ could reduce fuel consumption and related CO2 emissions. We envisage that this strategy opens an essential avenue for “Green Tire Technology” towards the substantial pollution abatement from ELTs and reduces the toxic ZnO.
Solar‐driven seawater production H2O2 catalyzed by hydroxyl functionalized crystalline K‐doped g‐C3N4 under ambient conditions
Three hydroxyl functionalized crystalline K-doped g-C3N4 were designed and synthesized, which exhibited high photocatalytic activity for production H2O2 directly from natural seawater. Under optimized conditions, the highest H2O2 production rate of 1622 μmol g−1 h−1 for duration of 10 h was obtained.
Three hydroxyl functionalized crystalline K-doped g-C3N4 were synthesized from dicyandiamide, melamine, ammonium chloride, ammonium oxalate, and ammonium citrate via ionothermal polycondensation using KCl as molten salt under N2 atmosphere, which served as efficient recyclable photocatalysis realized that generating H2O2 directly from seawater with air by 2e− ORR pathway under stimulated solar irradiation in ambient conditions. Under optimized conditions, the highest H2O2 production rate of 1622 μmol g−1 h−1 for duration of 10 h was obtained. The cycling performances of HPCN-2 displayed reusable for five times without noticeably loss of its catalytic activity. This work presents a real safer, sustainable, and economical approach for production of H2O2 directly from abundant natural seawater.
Formation and Effects of Upstream DNA‐RNA Base Pairing in Telomerase
Telomere elongation by telomerase consists of two types of translocation: duplex translocation during each repeat synthesis and template translocation at the end of repeat synthesis. Our replica exchange molecular dynamics simulations show that in addition to the Watson-Crick interactions in the active site, templating RNA can also form base pairs with the upstream regions of DNA, mostly with the second upstream DNA repeat with respect to the 3' end. At the end of the repeat synthesis, dG10-P442 and dG11-N446 hydrogen bonds form. Then, active site base pairs dissociate one by one and the RNA bases reanneal with the complementary base on the upstream DNA repeat. For each dissociating base pair a new one forms, conserving the number of base pairs during template translocation.
Light in SmI2‐mediated chemistry: Synthetic applications and mechanistic studies
Photoexcitation of SmI2 and related SmII-based reagents generate a potent single electron transfer reagent capable of reductions which are otherwise impossible in the ground state. This review article illustrates the role of light in synthetic reactions mediated by SmI2. Advances made in understanding mechanistic aspects of these reactions are also described.
Abstract
SmI2 is a versatile reagent in single electron transfer-mediated reductive transformations. Photoexcitation of SmI2 generates a reactive excited state capable of transferring an electron to substrates that are recalcitrant towards accepting electrons. Synthetic results unequivocally indicate light as a green and sustainable promoter of SmI2-mediated chemistry, with the potential to replace the suspected carcinogen hexamethylphosphoramide (HMPA). Rate constants of photoinduced electron transfer from SmI2 are in the range of 107–109 M−1 s−1, which are an order of magnitude higher in comparison with the ground state process. Recent advancement in EuII- and CeIII-based photo-redox catalysis rejuvenated the area of photo-catalyzed reactions of low-valent lanthanides. This review article aims to illustrate the role of photoexcitation on SmI2-mediated reductive transformations.
Biological effects and crystal X‐ray study of novel Schiff base containing pentafluorophenyl hydrazine: In vitro and in silico studies
A novel Schiff base namely 3,5-di-tert-butyl-6-((2-(perfluorophenyl) hydrazono) methyl) phenol was successfully synthesized and characterized using FTIR and 1H-NMR, 13C-NMR, and 19F-NMR. The crystal structure analysis of the Schiff base compound was also characterized with single crystal X-ray diffraction studies and supported the spectroscopic results. The cytotoxicity, anti-bacterial properties, and enzyme inhibition of the compound were also investigated. The molecular docking studies were performed in order to explain the interactions of the synthesized compound with target enzymes. The newly synthesized hydrazone derivative Schiff base compound showed high cellular toxicity on MCF-7 and PC-3 cells. Also, this compound caused low antibacterial effect on E. coli and S. aureus. Besides, the compound exhibited the inhibitory effect against pancreatic cholesterol esterase and carbonic anhydrase isoenzyme I, II with IC50 values 63, 99, and 188 µM, respectively. Consequently, it has been determined that the prepared Schiff base is an active compound in terms of cytotoxicity, enzyme inhibition, and anti-bacterial properties. These results provide preliminary information for some biological features of the compound and can play a major role in drug applications of the Schiff base compound.
Unveiling the Collaborative Strategy and Synergistic Effects of Pd/V2O5‐fAC towards glycerol electrooxidation
A series of Pd nanoparticles supported on V2O5 immobilized on functionalized carbon, %Pd (1, 3, and 5) and %V2O5 (10, 20, and 30), were prepared by sodium borohydride-assisted microwave polyol synthesis for glycerol oxidation reaction (GlyOR) in an alkaline medium. Electrocatalysts loading, temperature, V2O5 immobilization, and their synergistic effect on the electrocatalytic performance are systematically studied. The electrocatalysts' morphology and electronic properties were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, Transmission electron microscopy, and X-ray photoelectron spectroscopy. A significantly improved GlyOR is observed with increased V2O5 content and Pd percentage. The 5%Pd/30%V2O5–fAC showed the highest mass activity of 2157.3 mA.mg-1Pd, a more negative onset potential of 0.62 VRHE, versus the commercial equivalent, and possessed high stability and durability. The increase in electrocatalytic activity is attributed to the effective immobilization of V2O5 on fAC efficient synergism between Pd and V2O5, strong metal support interaction (SMSI), and great exposure of the electroactive sites. The results herein contribute significantly to the understanding of the physicochemical and electrochemical effects of metal oxide immobilization, microwave irradiation, %Pd/%Metal oxide optimization, and SMSI on metal oxide-carbon hybrid electrocatalysts for GlyOR, opening new avenues for fabricating high-performance direct alkaline glycerol fuel cells.
Transition‐Metal‐Catalyzed 1,2‐Diaminations of Olefins: Synthetic Methodologies and Mechanistic Studies
1,2-Diamines are synthetically important motifs in organo-catalysis, natural products, and drug research. Continuous utilization of transition-metal based catalyst in direct 1,2-diamination of olefines, in contrast to metal-free transformations, with numerous impressive advances made in recent years (2015-2023). This review summarized contemporary research on the transition-metal catalyzed/mediated [e.g., Cu(II), Pd(II), Fe(II), Rh(III), Ir(III), and Co(II)] 1,2-diamination (asymmetric and non-asymmetric) especially emphasizing the recent synthetic methodologies and mechanistic understandings. Moreover, up-to-date discussion on (i) paramount role of oxidant and catalyst (ii) key achievements (iii) generality and uniqueness, (iv) synthetic limitations or future challenges, and (v) future opportunities are summarized related to this potential area.