Article
Chemistry, Inorganic & Nuclear
Kei Ikeda, Kazunari Yoshizawa, Yoshihito Shiota
Summary: The benzene hydroxylation catalyzed by ruthenium-substituted Keggin-type polyoxometalates was investigated, showing high chemoselectivity and the heteroatom effect on the reaction's activation free energy. Replacing Si with other elements can significantly affect the efficiency of the catalyst for benzene hydroxylation.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Ying Xin, Lu Cheng, Yanan Lv, Junxiu Jia, Dongxu Han, Nana Zhang, Jin Wang, Zhaoliang Zhang, Xiao-Ming Cao
Summary: This study investigates the effect of different exposed crystal facets on the catalytic performance of Mn2O3 for NO oxidation by constructing rod- and particle-like Mn2O3 nanocrystals. The results show that different crystal structures lead to diverse catalytic behaviors of Mn2O3, especially in terms of poisoning resistance. Additionally, this work provides valuable design principles for future studies to improve other metal oxide catalysts.
Article
Engineering, Environmental
Chuanyu Yan, Abdelhamid Sayari
Summary: One of the most critical challenges in applying amine-based CO2 adsorbents on a large scale is their long-term stability and oxidative degradation. In this study, the oxidation of polyethylenimine (PEI) was investigated using various analysis techniques, and the presence of radical species and their increase in the presence of transition metal catalysts were observed for the first time. Significant amounts of CO2, water, and ammonia were also detected. Surprisingly, although epoxybutane (EB) and polyvinyl alcohol (PVA) improved the oxidation resistance of PEI, they did not reduce the amount of radical species. Theoretical calculations suggested that PEI is more prone to oxidation due to its weaker C-H bonds. The findings provide insights into the oxidation and antioxidation mechanisms of amines and offer clues for further improvement.
CHEMICAL ENGINEERING JOURNAL
(2024)
Article
Chemistry, Physical
Chen Manjiao, Zhang Zhengfu, Hu Xinjun, Tian Jianping, Wang Jingsong, Wan Rundong, Zhou Xian, Zhou Xinjun, Shen PeiLun, Liu Dianwen
Summary: The study demonstrates the significant role of water molecules in the oxidation reaction on the surface of arsenopyrite, accelerating the surface oxidation process and resulting in the formation of hydroxylated oxidation products.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yuting He, Ding Jiang, Xue Li, Jing Ding, Hongping Li, Hui Wan, Guofeng Guan
Summary: This study successfully prepared highly efficient catalysts using ternary copolymerized bifunctional poly(ionic liquid)s (TBPILs) rich in hydroxyls, halogen anions and tertiary N, achieving efficient reactions between CO2 and carbonates. Additionally, the study explored the effects of basic sites on CO2 conversion.
JOURNAL OF CO2 UTILIZATION
(2021)
Article
Chemistry, Physical
Xiaodong Zhang, Fukun Bi, Ziqiao Zhu, Yang Yang, Shenghao Zhao, Jinfeng Chen, Xutian Lv, Yuxin Wang, Jingcheng Xu, Ning Liu
Summary: The 3Mn2Ce catalyst shows superior catalytic performance and stability under high humidity conditions, mainly attributed to the formation of a solid solution between Ce and Mn species and better reducibility. The introduction of water can promote toluene mineralization by activating oxygen vacancies and facilitating the degradation pathway of toluene.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Applied
Pierre-Olivier Bussiere, Jean-Luc Gardette, Geraldine Rapp, Claire Masson, Sandrine Therias
Summary: Chitosan films were subjected to accelerated artificial weathering in the presence of oxygen, resulting in changes in chemical structure, formation of gluconolactone derivatives, detection of low molecular weight photoproducts, occurrence of crosslinking reactions, and variations in mechanical and surface properties. These changes were observed and correlated at molecular scale, showing a reduction in macroscopic properties.
CARBOHYDRATE POLYMERS
(2021)
Article
Chemistry, Physical
Die Bai, Man Li, Rong-Zhen Liao
Summary: The merging of transition-metal-catalyzed C-H bond activation with electro-oxidation has become a promising approach for oxidative C-H bond functionalization. However, the specific effects of electro-oxidation on the reaction mechanism of transition-metal catalysis have rarely been studied. In this computational study, the rhodium-catalyzed electrochemical C-H phosphorylation of 2-phenylpyridine by diphenylphosphine oxide was investigated to reveal the mechanistic details. The calculations showed that C-H activation prefers to occur at the Rh(III) state, P-H activation at the Rh(IV) state, and reductive elimination at the Rh(V) state. The mechanistic insights obtained from this study are valuable for understanding transition-metal-catalyzed electro-oxidative C-H bond functionalization.
Article
Environmental Sciences
Teng-ge Mi, Yang-wen Wu, Xin-yue Zhou, Bin Hu, Li Zhao, Qiang Lu
Summary: The V2O5/TiO2 based SCR catalysts have promising denitrification capability and can also oxidize carbon monoxide (CO) in the flue gas. Adding transition metals such as Fe and Co to the traditional SCR catalysts can further enhance their catalytic oxidation ability for CO. The activation barriers of the rate-determining steps for CO oxidation on Fe-V2O5/TiO2 and Co-V2O5/TiO2 are lower than that of Mo-V2O5/TiO2, indicating that Fe and Co dopants can promote the CO oxidation activities of the modified SCR catalysts. The electronic structure analysis confirms that Fe and Co dopants can cause electron distribution change with strong oxidation ability at the active oxygen sites.
Article
Chemistry, Multidisciplinary
Lanping Gao, Xiaolu Chen, Dongru Sun, Hua Zhao, Yufen Zhao, Wonwoo Nam, Yong Wang
Summary: Theoretical study on the iron(III)-iodosylarene complex revealed its chameleon-like behavior in oxygenation of cyclohexene, adapting roles as a 2e-oxidant or an oxygen donor. It was found to activate C-H bond via a novel hydride transfer process, forming a carbonium intermediate triggering different pathways, and activate C=C bond as a normal oxygen donor to present the epoxide product. These mechanistic findings enrich the non-rebound scenario in bioinorganic chemistry and explain famous Valentine's experiments.
CHINESE CHEMICAL LETTERS
(2021)
Article
Engineering, Environmental
Xiaolan Zeng, Yu Meng, Xiaozi Sun, Fang Guo, Mi Yang
Summary: This study investigated the degradation behavior of enoxacin in aqueous solution using UV-activated persulfate, with a focus on the role of sulfate and hydroxyl radicals in the degradation process. Experimental results showed that hydroxyl radicals played a major role in enoxacin degradation, while sulfate was found to be more reactive in degrading enoxacin. The combination of experimental results and theoretical calculations revealed the main reaction mechanism of enoxacin degradation.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Xi Yue, Yong Li, Hongxia Li, Chenhong Ma, Xiuhua Zhang
Summary: In this study, the oxidation mechanism of Si-Al2O3-fused mullite containing Ti2O3 composite was investigated by heat-treating the material at different temperatures. The results showed that the composite exhibited excellent oxidation resistance at high temperatures due to the formation of an oxide layer and a transition layer that could absorb and filter oxygen, preventing oxidation of the interior.
MATERIALS CHARACTERIZATION
(2023)
Article
Energy & Fuels
Si Wang, Zhen Ren, Haisong Feng, Yawen Shi, Yuan Deng, Pengxin Pu, Yusen Yang, Lifang Chen, Xin Zhang
Summary: This study investigates the reaction mechanism of glycerol oxidation to glyeric acid over the catalytic systems of Au/CeO2_X and Pt/CeO2_X through density functional theory (DFT) calculations. The results show that the Au/CeO2_X interface facilitates the dehydrogenation reaction of C_ H/O_ H bond, leading to the formation of glyceraldehyde, while Pt/CeO2_X is more favorable for the oxidation of glyceraldehyde to glyceric acid. This work provides valuable insights into the interfacial synergy effects of supported catalytic systems and the reaction mechanism of glycerol oxidation, which can guide the selection of catalysts and solvent conditions for selective oxidation reactions.
Article
Chemistry, Physical
Denis P. Porfiriev, Valeriy N. Azyazov, Alexander M. Mebel
Summary: Ab initio CCSD(T)-F12/cc-pVTZ-f12//B3LYP/6-311G(d,p) calculations were combined with RRKM-ME calculations to investigate the mechanism and kinetics of the n-C4H5 + O-2 reaction. The results show the reaction is fast, with the main products being 1-oxo-n-butadienyl + O and acrolein + HCO, with a cumulative yield exceeding 90% at temperatures above 1500 K. Both products are formed through different pathways involving significant reorganization of the molecule's structure.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Engineering, Environmental
Qianchen Wang, Chen Ling, Jingbo Li, Hongcai Gao, Zongguo Wang, Haibo Jin
Summary: The novel NASICON-related structure Na4MnAl(PO4)(3) shows high specific capacity and voltage plateaus, with the sodium ion storage mechanism and diffusion path investigated. The DFT calculations suggest a potential for higher voltage and specific capacity, making it a strong contender for cathode material in sodium-ion batteries.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
Mona Jalali, Farshad Shiri, Alex C. Bissember, Brian F. Yates, Alireza Ariafard
Summary: Density functional theory (DFT) was used to investigate the mechanism of the efficient hydroalkylation of styrene with acetylacetone in the presence of a bismuth catalyst. The results show that the mechanism is fundamentally different from the analogous gold-catalyzed reaction and is characterized by bismuth coordinating to the oxygens of acetylacetone to form a chelated complex. The activation energy for the reaction with bismuth via the enol isomer of acetylacetone is much lower compared to the ketone isomer.
Article
Chemistry, Inorganic & Nuclear
Howard Z. Ma, Allan J. Canty, Richard A. J. O'Hair
Summary: A near thermal two-step catalytic cycle for the selective release of hydrogen from formic acid was revealed. Mononuclear copper hydride anions were found to react with formic acid to yield copper formate anions and H-2. The copper formate anions can decarboxylate to reform the copper hydride, thus closing the catalytic cycle.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Jackson S. Henneveld, Farshad Shiri, Alireza Ariafard, Nigel T. Lucas, Alex C. Bissember, Bill C. Hawkins
Summary: The investigation and formalization of the distinctive dipole-transmissive dipolar cycloaddition (DTDC) methodology is reported. A DTDC procedure was developed by taking advantage of the structural complementarity of azide and diazoalkane 1,3-dipoles. This method allows for the rapid construction of functionalized polycyclic N-heterocycles through intramolecular azide-alkene 1,3-dipolar cycloadditions followed by N-derivatization and subsequent 1,3-dipolar cycloadditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Farshad Shiri, Alireza Ariafard
Summary: 1,6-enynes can be cyclized to yield cyclopropyl ketones using PhI(OAc)(2) (PIDA) in the presence of Pd(OAc)(2) as a catalyst. However, when 1,6-enynes are substituted by a hydroxy group at the alpha-position, polycyclic oxa-heterocycles are formed instead. This study aims to investigate the mechanistic aspects of these transformations and reveals that the change in chemoselectivity is due to the electronic nature of the Pd catalyst changing from pi-philicity to oxophilicity during the catalytic cycle.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Alex C. Bissember, Angus Olding, Curtis C. Ho, Nigel T. Lucas, Allan J. Canty
Summary: By covalently tethering a supporting ligand to a boron nucleophile, typically elusive and kinetically unstable Suzuki-Miyaura (SM) pretransmetalation species were able to be controlled. This strategy allowed for the synthesis of an organonickel(II) boronate pretransmetalation intermediate and its characterization through X-ray crystallography. Performing reactions in the presence of carbon monoxide led to pretransmetalation intermediates in carbon-ylative SM reactions-aroylmetal boronates, enabling the determination of the X-ray crystal structures of an aroylnickel(II) boronate (and an aroylpalladium(II) boronate).
Article
Chemistry, Applied
Janina Bucher, Thomas Wurm, Kaveh Farshadfar, Michael Schukin, Georgios Uzunidis, Matthias Rudolph, Frank Rominger, Alireza Ariafard, A. Stephen K. Hashmi
Summary: By using the sterically highly demanding steering ligand IPr* on a gold(I) center, a 6-endo-dig cyclization pathway can be induced in 1,5-diynes with terminal alkyne moieties. The resulting aurated naphthyl cations are utilized for intermolecular C-C bond formation through C-H insertion of aromatic and aliphatic C-H bonds. The mechanisms of these transformations were studied through quantum chemical calculations.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Inorganic & Nuclear
Allan J. J. Canty, Alireza Ariafard
Summary: Density functional theory was employed to study the mechanistic of the oxidation of pincer complex Pd-II(mer-NCN)(K-1-O2CPh) by diphenyliodine(III) triflate in the presence of bicarbonate base. The results suggest that concerted oxidative addition by Ph2I(OCO2H) is favored over a Ph+ transfer mechanism to initially form octahedral PhPdIV(mer-NCN)(K-1-O2CPh){I(Ph)(& BULL;& BULL;& BULL;OCO2H)-I}. Interaction of bicarbonate with the iodine center has little impact on the concerted transition state but disrupts the Ph+ transfer mechanism.
Article
Multidisciplinary Sciences
Lina Song, Xianhai Tian, Kaveh Farshadfar, Farshad Shiri, Frank Rominger, Alireza Ariafard, A. Stephen K. Hashmi
Summary: Here, the authors developed a metal-free, visible light-mediated cascade reaction for the preparation of azepinone derivatives. The reaction involves a photochemical generation of 2-aryloxyaryl nitrene, [2 + 1] annulation, ring expansion/water addition cascade reaction without using any metal catalyst. The reaction shows broad scope and the obtained products can undergo divergent transformations to afford other related compounds. A computational study suggests a pathway involving a step-wise aziridine formation, followed by a ring-expansion to the seven-membered heterocycle. Finally, water is added in a regio-selective manner, accelerated by the added TsOH. Photochemical nitrene transfer offers a green avenue for heterocyclic syntheses.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yang Yang, Allan J. Canty, Richard A. J. O'Hair
Summary: Multistage mass spectrometry (MSn) experiments were conducted to investigate the extrusion-insertion reactions of a palladium complex. The results showed that the organopalladium cation was formed and reacted with phenylmethylketene to produce an enolate. Further analysis revealed the formation of an acyl complex. However, attempts to develop a palladium-mediated one-pot synthesis of ketones proved challenging due to low yields and side product formation.
AUSTRALIAN JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Nusaybah Alotaibi, Rasool Babaahmadi, Milan Pramanik, Tanja Kaehler, Ayan Dasgupta, Emma Richards, Alireza Ariafard, Thomas Wirth, Rebecca L. L. Melen
Summary: In this study, the C3-allylation of indoles using allylic esters was achieved using B(3,4,5-F3H2C6)(3) as the catalyst. A total of 25 examples of C3-allylated products were obtained with yields up to 97%. The mechanism of the reaction was investigated through detailed Density Functional Theory (DFT) studies.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Farshad Shiri, Alireza Ariafard
Summary: This study demonstrates that the oxidative addition of hypervalent iodine PhICl2 to Au(I) complexes LAuAr follows an unprecedented stepwise mechanism. The energy of the Au(I) d(x2-y2) orbital determines the ease of the oxidative addition reaction; the fewer electron-withdrawing substituents present on the Ar ligand, the higher the energy of the d(x2)-(y2) orbital and the easier the oxidative addition.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Farshad Shiri, Curtis C. Ho, Alex C. Bissember, Alireza Ariafard
Summary: This study investigates the reaction between gold(I) complexes and hypervalent iodine(III) reagents and uncovers a transmetalation mechanism between gold(I) and gold(III) complexes. It establishes a theoretical model that can predict the outcomes of reactions involving these complexes, providing a foundation for advancements in this field.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Howard Z. Ma, Allan J. Canty, Richard A. J. O'Hair
Summary: This study investigates the possibility of selective decarbonylation of formic acid mediated by molybdate anions in a formal catalytic cycle. The results show that dimolybdate anions can effectively catalyze the decomposition of formic acid, yielding carbon monoxide and water.
DALTON TRANSACTIONS
(2023)