Article
Chemistry, Multidisciplinary
Grace B. Panetti, Patrick J. Carroll, Michael R. Gau, Brian C. Manor, Eric J. Schelter, Patrick J. Walsh
Summary: The super electron donor ability of 2-azaallyl anions has been discovered and applied in various reactions, while the redox properties of these species have been rarely studied. Electrochemical analysis revealed an oxidation wave at -1.6 V versus Fc/Fc(+), lower than the predicted potential, and led to the design of the first stable acyclic 2-azaallyl radical. These findings highlight the importance of reorganization energy in the development of potent organic reductants.
Article
Chemistry, Inorganic & Nuclear
Chenghuan Liu, Rui Liu, Chenfeng Wang, Yanyan Tang, Zheng-Feng Zhang, Ming-Der Su, Yan Li
Summary: This study investigated the reactions of amidinate silylene chloride with TMS- and Ph-ethynyl lithium salts, resulting in the formation of silacycles. The different structures of the products were attributed to the electronic or steric properties of the ethynyl substituents, and the formation mechanisms were analyzed using DFT calculations. Additionally, sequential reactions and reactions under O2 led to the exclusive formation of ethynylsilanes, indicating a prevention of further conversion of ethynylsilylenes to silacycles.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jae-Hwan Kwak, Yohan Park, Jee Eun Hong, Jisong Yoon, Woohyun Baek, Kyumin Kim
Summary: Here, we describe a direct electrochemical C(sp3)-H lactonization of 2-alkylbenzoic acids for the synthesis of phthalides. This reaction utilizes a graphite anode, dichloromethane (DCM) solvent, hexafluoroisopropanol (HFIP) cosolvent, and n-Bu4NClO4 electrolyte to provide a wide substrate scope of 2-alkylbenzoic acids bearing primary to tertiary C(sp3)-H bonds. Our synthetic approach offers a simple, intuitive, and atom-economical protocol for the synthesis of various phthalides (25 examples, up to 92% yield) and other 5-and 6-membered lactones (10 examples, up to 83% yield).
Article
Chemistry, Multidisciplinary
Kai-Meng Liu, Peng-Yu Wang, Zhen-Yan Guo, De-Cai Xiong, Xian-Jin Qin, Miao Liu, Meng Liu, Wan-Ying Xue, Xin-Shan Ye
Summary: We report a visible-light-promoted 2-deoxyglycosylation reaction of alcohols with glycals, which exhibits high efficiency, excellent stereoselectivity, and the capability to synthesize glycosylated compounds with different chain lengths.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Moushakhi Ghosh, Srinu Tothadi, Shabana Khan
Summary: The synthesis and characterization of a new carbazole substituted amidinatosilylene and its coinage metal complexes were reported in this work. Solid-state structures were validated through single-crystal X-ray diffraction studies and mass spectroscopy, with additional DFT studies for understanding the bonding scenarios.
Article
Chemistry, Physical
Svenja-K Otto, Yannik Moryson, Thorben Krauskopf, Klaus Peppler, Joachim Sann, Juergen Janek, Anja Henss
Summary: Research indicates that a nanometer-thick passivation layer on the surface of lithium metal consists of an outer lithium hydroxide and carbonate layer, and an inner region rich in lithium oxide. The thickness and composition of the passivation layer depend on treatment and storage conditions. Guidelines for experimental design and data interpretation are provided to ensure reliable and comparable experimental results.
CHEMISTRY OF MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Jia Li, Ezra Alvianto, Yi Hou
Summary: This article discusses the development history, efficiency improvement, and commercialization challenges of perovskite/silicon tandem solar cell technology, emphasizing the importance of improving efficiency and accelerating commercialization.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Edzordzi Kwame Gikunoo, Dabin Han, Mohanraj Vinothkannan, Sangaraju Shanmugam
Summary: Low-cost, durable, and high-performance membranes are urgently needed for zinc bromine redox flow battery (ZBFB) applications. By incorporating perovskite-structured cerium titanate nanoparticles dispersed on smooth carbon nanofibers (p-CT/CNF) with varying carbon content into the polymer matrix, the sulfonated poly (ether ether ketone), SPEEK, backbone is protected, the crossover of active species is reduced, and the selectivity of the composite membrane is improved. Additionally, with a nanofiller loading of 0.5 wt%, the SP-p-CT350 membrane demonstrates stable battery performance across 500 cycles at a current density of 40 mA cm-2, with an outstanding energy efficiency of 81.13%.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Organic
Stefan Herzog, Alexander Hinz, Frank Breher, Joachim Podlech
Summary: In this study, an air- and moisture-stable helical radical was synthesized and its properties and spectra were determined. The results showed that this radical exhibited good stability, weak triradical character, and significant antiaromaticity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Md Elius Hossain, Zhifang Guo, Jun Wang, Glen B. Deacon, Peter C. Junk, Dominic Diether, Reiner Anwander
Summary: Eta(6)-arene(iodido-/bromido-aluminato)lanthanoid(III) complexes were prepared by reacting aluminium triiodide or aluminium tribromide with corresponding lanthanoid metals and halogenated ethanes in an arene solution. The first X-ray crystal structures of these complexes were reported. The lanthanoid atom in the complexes is coordinated by an eta(6)-arene and three chelating tetrahalidoaluminato ligands. However, the catalytic performance of these complexes towards isoprene polymerization was found to be lower compared to other halogenidoaluminatolanthanoid(III) complexes.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Lei Chen, Yuan Yang, Fei Li, Fei Jin, Bin He, Jun Yang
Summary: This study presents a novel synthetic route for producing a stable and versatile cyclopropene precursor, addressing the challenges related to instability and difficulties in scale-up processes. The cyclopropene precursor enables the easy synthesis of various cyclopropenes with different functional groups and handles. Among the synthesized cyclopropene derivatives, the 1-methylcyclopropene uracil nucleoside derivative 40 exhibited the highest second-order kinetic constant when reacting with the 5-TAMRA-Tz fluorescent dye.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Applied
Marcin Szala, Julia Modrzejewska, Aleksandra Grzelakowska, Jolanta Kolinska, Radoslaw Michalski, Angelika Artelska, Adam Sikora, Radoslaw Podsiadly
Summary: Multiple studies have shown that reactive oxygen and nitrogen species (RONS) play a role in tumor formation through redox signaling. This study reports the synthesis of new luciferin-based probes for the detection of nitroxyl. The probes showed reactivity and selectivity towards nitroxyl, and can be used for bioluminescence imaging in luciferase-transfected cells.
Article
Chemistry, Organic
Iago Pozo, Agustin Cobas, Diego Pena, Enrique Guitian, Dolores Perez
Summary: A complex mechanism involving the generation of an intermediate ketocarbene, which adds to the cyclopentadienone to give an isolable tricyclic intermediate, followed by thermal rearrangements, is proposed to explain the formation of the product in the reaction of 2-(trimethylsilyl)thiophen-3-yl triflate with CsF in the presence of 2,3,4,5-tetraphenylcyclopentadienone. The intermediacy of the hypothesized 5-membered hetaryne is discarded based on detailed experimental and computational studies, suggesting a different pathway for the reaction.
Article
Chemistry, Multidisciplinary
Jan M. Rall, Max Lapersonne, Marcel Schorpp, Ingo Krossing
Summary: This article reports the synthesis and characterization of nickelocenium cations. Diamagnetic [NiCp2]2+ represents the first example of an unsubstituted parent metallocene dication. The salts were generated and characterized using various experimental methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
V. Mahesh Krishnan, Dimitar Y. Shopov, Caitlin J. Bouchey, Wilson D. Bailey, Riffat Parveen, Bess Vlaisavljevich, William B. Tolman
Summary: By modulating the properties of ligands, Cu(III) complexes bearing an oxygen-based auxiliary ligand were successfully stabilized and characterized for the first time, showing enhanced stability and slower reactivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Sultana Bedoura, Hong-Wei Xi, Ho Wee Goh, Kok Hwa Lim
Summary: Using density functional theory (DFT) method, the study investigated the properties of triazole-based donor-acceptor (DA) pi-conjugated molecules, revealing that certain acceptors with specific substituents exhibit stronger conjugation and electron delocalization, leading to lower LUMO energies. The introduction of heteroatoms such as S and Se in the acceptor structure significantly reduces the bandgap. Additionally, polymers composed of Y4 donor and X1 acceptor fragments show promising potential for heterojunction organic solar cell applications.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Inorganic & Nuclear
Hong-Wei Xi, Sultana Bedoura, Mahasin Alam Sk, Kok Hwa Lim
Summary: The ring strain, pi-sigma hyperconjugation, and ring-opening reactions of silicon-substituted cyclobutenes were studied systematically. The strength of the ring strain was characterized by the deviation of bond angles and bond lengths, while pi-sigma hyperconjugation was found to relax the ring strain. The thermal ring opening reactions were predicted to follow a symmetry-allowed mechanism, with the contribution of bond energy determining whether the process is endothermic or exothermic.
Article
Engineering, Geological
Jing Ren, Huan He, Kai-Chung Lau, Kostas Senetakis
Summary: Research shows that artificially coating sand grains with iron oxides significantly alters the roughness and hardness of the grains, affecting inter-particle friction and normal contact stiffness. The friction coefficient of the coated specimens clearly depends on the magnitude of normal load and loading history, likely due to factors such as contact breakage, plowing damage, and surface debris buildup.
Article
Chemistry, Multidisciplinary
Chao Wang, Yuzhuo Chen, Daijian Su, Wai-Lun Man, Kai-Chung Lau, Lianhuan Han, Liubin Zhao, Dongping Zhan, Xunjin Zhu
Summary: A new molecular electrocatalyst with highly dispersed CoN4 sites was synthesized for CO2 reduction reaction. The catalyst shortens the electron transfer pathway, accelerates the redox kinetics, and improves durability. Experimental results showed that it achieved high current density and CO conversion rate in commercial flow cells.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yunling Pan, Miaomiao Zhou, Rui Wang, Dan Song, Shek-Man Yiu, Jianhui Xie, Kai-Chung Lau, Tai-Chu Lau, Yingying Liu
Summary: In this study, a new type of seven-coordinate ruthenium-iodosylbenzene complex was reported, which exhibited high reactivity towards various organic substrates through undergoing O-atom transfer and C-H bond activation reactions. The X-ray crystal structure of this complex revealed a distorted pentagonal bipyramidal geometry. This work provides insights for the development of new highly reactive oxidizing agents based on seven-coordinate geometry.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jing Xiang, Yi Pan, Lu-Lu Liu, Li-Xin Wang, Huan Yang, Shun-Cheung Cheng, Shek-Man Yiu, Chi-Fai Leung, Chi-Chiu Ko, Kai-Chung Lau, Tai-Chu Lau
Summary: Although the oxidation of alcohols by metal nitrido complexes has not been studied extensively, this report demonstrates the visible-light-induced oxidation of primary and secondary alcohols to carbonyl compounds using a strongly luminescent osmium(VI) nitrido complex (OsN). The proposed mechanism involves the rate-limiting hydrogen-atom transfer from the alpha-carbon of the alcohol to OsN*. Attempts to catalytically oxidize alcohols by OsN* using PhIO as the terminal oxidant resulted in the formation of novel osmium(IV) iminato complexes where the nitrido ligand is bonded to a 6-carbon of the alcohol. Experimental and theoretical studies suggest that OsN* is reductively quenched by PhIO to generate highly active PhIO+ oxidant, which readily undergoes alpha- and 6- C-H activation of alcohols.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Engineering, Chemical
Muhammad Rithaudin Bin Yep Abu, Kok Hwa Lim
Summary: Managing teaching and research laboratories at universities is becoming increasingly complex, especially when they serve as hybrid laboratories that serve both functions simultaneously. To ensure safety and security, selected elements of process safety management were adopted to establish a strong approach to laboratory safety management. These elements were customized to meet the changing requirements of research activities and laboratory users, including undergraduates and researchers. The focus was on both user and technical aspects, covering employee participation and change management. The main objective was to cultivate and maintain a laboratory safety culture that safeguards all users and minimizes damage to assets.
PROCESS SAFETY PROGRESS
(2023)
Article
Chemistry, Multidisciplinary
Jie Yan, Zi-Qi Feng, Yixin Wu, Dong-Ying Zhou, Shek-Man Yiu, Chin-Yiu Chan, Yi Pan, Kai Chung Lau, Liang-Sheng Liao, Yun Chi
Summary: Efficient blue phosphors for OLEDs remain challenging. Researchers have synthesized a series of Ir(III) complexes and studied their structures and photophysical properties to overcome this challenge. Some of the emitters can undergo interconversion without decomposition in a specific solvent. The synthesized Ir(III) complexes exhibit good luminescence properties and show potential for making blue OLEDs.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Hongyan Zhao, Yi Pan, Kai-Chung Lau
Summary: This article proposes a theoretical procedure for accurately determining the reduction potentials of three metallocene couples. By calculating the gas phase ionization energy and the solvation free energy, the one-electron reduction potential is obtained. The SMD model yields the best estimation for the solvation free energy and provides reliable values for the reduction potentials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Optics
Yue Gao, Yi Pan, Shenyue Xu, Kai-Chung Lau, Hang Yuan, Zhenyu Yan, Dalong Guo, Dongmei Zhao, Xiaolong Zhu, Shuncheng Yan, Shaofeng Zhang, Zhongfeng Xu, Xinwen Ma
Summary: The three-body fragmentation of C2H23+ to H+ + C+ + CH+ resulting from CH and CC bond breaking is studied under 50-keV/u Ne8+ impact. All three fragments are detected in coincidence with a scattered projectile (either Ne7+ or Ne6+) using a reaction microscope, and their momentum vectors and kinetic energies are obtained. Four distinct structures are observed in the energy correlation spectra, indicating multiple fragmentation mechanisms contributing to the H+ + C+ + CH+ channel. Newton diagrams and Dalitz plots are used to trace these fragmentation mechanisms. It is found that both concerted fragmentation and sequential pathways involving CH bond breaking prior to CC contribute to this channel. The possible electronic states of the C2H23+ precursor that contribute to the identified fragmentation mechanisms are analyzed using quantum chemical calculations. Furthermore, the influence of collision dynamics between the projectile and target on the dissociation mechanisms is discussed by comparing the contributions from the T1I2 channel and the reversed T2I1 channel, where one electron is transferred while ionizing the other two. The T2I1 channel is observed to be more efficient in initiating fragmentation mechanisms with higher kinetic energy release.
Article
Chemistry, Multidisciplinary
Chao Wang, Yuzhuo Chen, Daijian Su, Wai-Lun Man, Kai-Chung Lau, Lianhuan Han, Liubin Zhao, Dongping Zhan, Xunjin Zhu
Summary: The new electrocatalyst EP-CoP shows improved efficiency and durability in CO2 reduction reactions by enhancing the dispersion of CoN4 sites and optimizing redox kinetics. In commercial flow cells, EP-CoP demonstrates excellent catalytic performance under various overpotential conditions.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Huatian Shi, Lin Cheng, Yi Pan, Chi-Keung Mak, Kai-Chung Lau, Tai-Chu Lau
Summary: This work investigates the effects of weak acid (such as CH3CO2H) and weak Lewis acid (such as Ca2+) on C-H bond activation by KMnO4. The results show that efficient oxidation of cyclohexane can be achieved in the presence of AcOH and Ca2+. DFT calculations reveal the hydrogen bonding and coordination between MnO4-, AcOH, and Ca2+. These activating effects may also apply to other metal-oxo species.
Article
Chemistry, Multidisciplinary
Chang Shen, Wasihun Menberu Dagnaw, Ching Wai Fong, Kai Chung Lau, Cheuk-Fai Chow
Summary: The oxidative catalytic halogenations of the C(sp(3))-H bond of alkanes promoted by Fe-III(acacen)Cl and Fe-III(acacen)Br in the presence of trifluoroacetic acid were investigated, involving four major steps with trifluoroacetic acid playing a key role in forming the high-valent iron-oxo intermediate and generating reaction selectivity.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jing Xiang, Jiang Zhu, Miaomiao Zhou, Lu-Lu Liu, Li-Xin Wang, Min Peng, Bi-Shun Hou, Shek-Man Yiu, Wai-Pong To, Chi-Ming Che, Kai-Chung Lau, Tai-Chu Lau
Summary: The photoreactions of a luminescent osmium(VI) nitrido complex, [Os-VI (N)(L)(CN)(3)](-) (OsN, HL = 2-(2-hydroxy-5-nitrophenyl)benzoxazole), with catechol (H(2)Cat) and hydroquinone (H(2)Q) result in the cleavage of strong C-OH bonds in dihydroxybenzenes and the conversion of coordinated cyanide to carbon monoxide.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Yunling Pan, Lin Cheng, Yi Pan, Wai-Lun Man, Shek-Man Yiu, Jianhui Xie, Kai-Chung Lau, Tai-Chu Lau
Summary: This study reports the first example of oxidative cleavage of primary amines by a ruthenium(VI) nitrido complex. The reaction is driven by the formation of stable NuN after the initial coupling of the amine N and the nitrido ligand.
DALTON TRANSACTIONS
(2022)
