RSC Advances
·
2013
·Vol. 4
·期 6
·3082-3089
·
IF 2.562
Weitong Cai,Hui Wang,Dalin Sun,Qingan Zhang,Xiangdong Yao,Min Zhu
Destabilization by the alkali metal hydroxides LiOH, NaOH, and KOH in the solid-state dehydrogenation of LiBH4 is reported. 6.5 wt% of hydrogen was liberated within 10 minutes at 250 °C. Destabilization originated from the interaction between H+ in [OH]− and H− in [BH4]−. A larger Pauling's electronegativity of the alkali metal (Li > Na > K) led to a greater acidity of the proton donor [OH]− site, and thus enhanced destabilization. The temperature of the predominant dehydrogenation was reduced to 207, 221, and 230 °C, for ball milled LiBH4–LiOH, 2LiBH4–NaOH, and 2LiBH4–KOH, respectively. The LiBH4: LiOH stoichiometry greatly affected the destabilization, by providing differing reaction pathways in LiBH4-xLiOH (x = 1, 1.36, 4). The incremental increase in the LiOH content of LiBH4-xLiOH increased the dehydrogenation rate, but the temperature increased from 207 °C (x = 1) to 250 °C (x = 4). 4.1 and 6.5 wt% of hydrogen was liberated within 10 minutes by LiBH4–LiOH and LiBH4–4LiOH, respectively. The incremental increase in dehydrogenation temperature was attributed to differing [BH4]−⋯[OH]− interactions, formed by the differing stoichiometric ratios.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2017
·Vol. 61
·期 3
·276-280
·
IF 4.132
Qi Guangyu,Wang Kai,Xiao Guanjun,Zou Bo
Pressure, as a thermodynamic parameter, provides an appropriate method to detect weak intermolecular interactions. The C–H···H–B dihydrogen bond is so weak that the experimental evidence of this interaction is still limited. A combination of in situ high pressure Raman spectra and angle-dispersive X-ray diffraction (ADXRD) experiments was utilized to explore the dihydrogen bonds in dimethylamine borane (DMAB). Both Raman and ADXRD measurements suggested that the crystal structure of DMAB is stable in the pressure region from 1 atm (1 atm=1.01325×10 5 Pa) to 0.54 GPa. The red shift of CH stretching and CH 3 distortion modes gave strong evidence for the existence of C–H···H–B dihydrogen bonds. Further analysis of Raman spectra and Hirshfeld surface confirmed our proposal. This work provided a deeper understanding of dihydrogen bonds. And we wish that high pressure could be applied to identify other unconfirmed hydrogen or dihydrogen bond.
研究领域:
化学
·
材料科学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 36
·22485-22491
·
IF 3.108
Hailiang Zhao,Shanshan Tang,Qun Zhang,Lin Du
The weak intermolecular interaction between 2,2,2-trifluoroethanol (TFE) and 3-chloro-2-methyl-1-propene (CMP) has been investigated by gas phase FTIR spectroscopy and DFT calculations. CMP offers two hydrogen bond docking sites to the hydrogen bond donor: the chlorine atom (O–H⋯Cl) and the CC π electron system (O–H⋯π). DFT calculations suggest that MeOH approaches CMP in five different orientations. The structural, energetic, and spectroscopic parameters of the most stable structures in each orientation were studied, and their binding energies range from −25.5 to −19.5 kJ mol−1. The docking to the π system is at least 1 kJ mol−1 more favored than the docking to the chlorine atom. The equilibrium constant for complexation (2.3 × 10−2) was determined from the experimental and calculated intensity of the OH-stretching transition. The Gibbs free energy of formation was found to be 9.3 kJ mol−1. The nature of the non-covalent interaction was analyzed with the atoms in molecules (AIM) method.
研究领域:
物理化学
·
结构化学
·
分子光谱学
·
量子化学计算
·
分子间相互作用
✓ 已验证
DOI
高影响因子
Asian Journal of Organic Chemistry
·
2018
·Vol. 7
·期 8
·1626-1634
·
IF 2.496
Wen-Jing Pan,Zhong-Xia Wang
Graphical Cut my bonds into pieces : The C−H benzylation of oxazoles and benzoxazoles with benzyl trimethylammonium triflates was performed under mild conditions via Pd-catalyzed C−H/C−N cleavage. The method exhibits a wide scope of substrates and good compatibility of functional groups. The C−H benzylation of oxazoles and benzoxazoles with benzylic ammonium triflates was performed in reasonable to good yields via Pd-catalyzed C−H/C−N cleavage. The method exhibits a wide scope of azoles and benzylic ammonium triflates. A range of functional groups including F, CF 3 , COOEt, C(O)NMe 2 , OMe, OPh, pyridyl and thienyl groups can be tolerated.
研究领域:
有机化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2025
·
IF 3.6
Jia-Wei Li,Shuai Shi,Xiao-Hong Chen,Mao-Gui Huang,Yong-Liang Ban,Hui Zhang,Yue-Jin Liu
Direct functionalization of native (N–H) indoles via C–H activation remains a challenge. Herein, we report a salicylaldehyde-promoted cobalt-catalyzed selective C2–H Heck reaction of native (N–H) indoles with both active and unactivated olefins in the presence of free N–H bonds. A series of structurally diverse C2-alkenylated native (N–H) indoles including natural product and drug derivatives were prepared directly and effectively without additional preprotection and deprotection procedures.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Jia'ni Gong,Pengfei Bai,Yifu Zhang,Qiushi Wang,Jingjing Sun,Yanyan Liu,Hanmei Jiang,Ziyi Feng,Tao Hu,Changgong Meng
Molybdenum trioxide (MoO 3 ) has been widely studied in the energy storage field due to its various phase states and unique structural advantages. Among them, lamellar α -phase MoO 3 ( α -MoO 3 ) and tunnel-like h -phase MoO 3 ( h- MoO 3 ) have attracted much attention. In this study, we demonstrate that vanadate ion (VO 3 - ) can transform α -MoO 3 (a thermodynamically stable phase) to h -MoO 3 (a metastable phase) by altering the connection of [MoO 6 ] octahedra configurations. h -MoO 3 with VO 3 - inserted (referred to as h -MoO 3 -V) as the cathode material for aqueous zinc ion batteries (AZIBs) exhibits excellent Zn 2+ storage performances. The improvement in electrochemical properties is attributed to the open tunneling structure of the h -MoO 3 -V, which offers more active sites for Zn 2+ (de)intercalation and diffusion. As expected, the Zn// h -MoO 3 -V battery delivers specific capacity of 250 mAh·g −1 at 0.1 A·g −1 and rate capability (73% retention from 0.1 to 1 A·g −1 , 80 cycles), well exceeding those of Zn// h -MoO 3 and Zn// α -MoO 3 batteries. This study demonstrates that the tunneling structure of h -MoO 3 can be modulated by VO 3 - to enhance the electrochemical properties for AZIBs. Furthermore, it provides valuable insights for the synthesis, development and future applications of h -MoO 3 .
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
SYNTHETIC COMMUNICATIONS
·
2018
·
IF 1.377
Xinyuan Ma,Qiong Mo,Jie Chang,Kai Xie
This paper mainly studied Pd-catalyzed regioselective chlorination of disubstituted 1,2,3-triazoles directed by the 1,2,3-triazole ring. A series of regioselective chlorinated products were synthesized in 47–86% yields using Pd(OAc)2 as a catalyst and CuCl2 as a chlorinated reagent. This method provides a new mean for the synthesis of 1,2,3-triazole halides which combines the formation of C-X bond with C-H activation.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2017
·
IF 4.849
Jian Cheng,Jun Sun,Jiekuan Yan,Song Yang,Pengcheng Zheng,Zhichao Jin,Yonggui Robin Chi
The metal-free catalytic functionalization of aromatic sp2-carbons and benzylic sp3-carbons remains challenging. Here we report a carbene-catalyzed functionalization of the 3-methyl sp3-carbon attached to 2-formyl-indoles. The reaction proceeds through an NHC-bound o-quinodimethane as the key intermediate generated from 2-formyl-3-methylindoles under oxidative conditions. Reactive ketones are found to be effective substrates to produce substituted hydropyrano[3,4-b]indoles in good to excellent yields.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2013
·Vol. 92
·期 5
·851-860
·
IF 1.003
Zhenhua Pan,Qizhou Cai,Qiang Luo,Xinwei Li
The mechanism and kinetics of synergetic effect in TiO 2 /O 3 /UV process on H-acid degradation were investigated. The experimental results showed that H-acid removal rate of TiO 2 /O 3 /UV process was the highest among TiO 2 /UV, O 3 /UV and TiO 2 /O 3 /UV processes. The investigation of reactions with suitable active species scavengers confirmed that H-acid was mainly oxidised by ozone and holes on TiO 2 in the TiO 2 /O 3 /UV process. The recombination between holes and electrons in TiO 2 reduced in the presence of ozone, as indicated by fluorescence emission spectra. Moreover, the intermediates generated during H-acid oxidation in various processes were analysed by LC/MSD trap. It is proposed that H-acid was oxidised to polyhydroxy aromatics, benzene carboxylic acids and quinoids in the first step. Then, saturated aliphatics carboxylic acids were formed and mineralised to inorganic compounds through the Photo-Kolbe reaction. Finally, a kinetic study on TiO 2 /UV, O 3 /UV and TiO 2 /O 3 /UV processes was conducted and it was confirmed that both ozonation and photocatalytic activity were improved in TiO 2 /O 3 /UV process because of the synergetic effect.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2024
·
IF 4.4
Xuyong Tang,Fengxi Li,Sijun Huang,Li Xu,Lei Wang,Yi Guo
Nicotinamide-adenine dinucleotide (NADH) as biomimetic units combined with copper ion to form laccases mimics (Cu-NADH). Cu-NADH has the enhanced activity of copper center to mediate aryl C–H amination using air as green oxidants. It could successfully catalyze oxidative coupling between different aromatic compounds and 4-phenylurazole (yield: 72 ∼ 91 %). Recycling catalytic ability (up to 6 times) showed its excellent stability. The Cu-NADH nanozyme was certificated to catalyze C–H amination effectively, and highlighted that it was a proper way to design catalysts according to enzyme-like catalyzing non-natural reaction.
研究领域:
生物化学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Dai Sun,Yu-Le Wang,Peng-Yue Zhu,Hai-Tao Ren,Yong Liu,Song-Hai Wu,Shao-Yi Jia,Xu Han
Mechanisms involved in the photocatalytic oxidation of As(III) are complicated in that various oxidizing species (such as h+, •OH, and O2•–) have been suggested to play important roles in different photocatalytic systems. In this study, Bi2.15WO6 shows high reactivity in the photocatalytic oxidation of As(III) under visible light. Quenching experiments indicate that apart from h+, the surface superoxo (≡Bi–OO•) and peroxo species (≡Bi–OOH) formed on Bi2.15WO6 also contribute to As(III) oxidation. The increased production of H2O2 with increasingly consumed As(III) or with the addition of H-donors such as glucose and various phenolics further reveals that H-abstraction from As(III) or H-donors to ≡Bi–OO• and then to ≡Bi–OOH is an important pathway involved in H2O2 production and As(III) oxidation. In addition, various characterizations confirm that the As(III)–O–Bi(III) surface complexes formed on Bi2.15WO6 enhance the photocatalytic reactivity of Bi2.15WO6 via the ligand-to-metal charge transfer pathway. We therefore suggest that dissolved oxygen is sequentially reduced to ≡Bi–OO• and then to ≡Bi–OOH on Bi2.15WO6, accompanied by H-abstraction from adsorbed or aqueous As(III) to ≡Bi–OO• and ≡Bi–OOH with the formation of H2O2 and the oxidation of As(III). This work enriches our understanding of the mechanisms involved in the photocatalytic oxidation of As(III).
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Tarek A. Gad-Allah,Ruiyang Zhang,Yi Wang,Ying Zhou
Various factors control the photocatalyst efficiency including the lifetime of photogenerated charge carriers, photocatalyst surface energy, and light harvesting efficacy. In this study, the defective (001)-TiO 2 -x/h-BN composite was synthesized by a facile one-pot method to merge the fantastic features of the reactive metastable (001) facet and self-defects in TiO 2 anatase crystals with the 2D h-BN. Pure anatase phase of TiO 2 was obtained by the suggested preparation method, which contains ∼33 % of the exposed (001) facet. The predominancy of oxygen vacancy in TiO 2 crystals was proved experimentally and theoretically by the DFT calculations. The defects in TiO 2 along with the incorporated h-BN caused better light harvesting and longer charge lifetime. The prepared defective (001)-TiO 2 -x/h-BN was applied efficiently for NO removal with very limited release of the toxic NO 2 by-product as an environmental application. The detected oxygen vacancy in TiO 2 along with h-BN were found to play a synergistic enhancement for NO removal. However, more defects reduced the overall activity because of rapid oxidation of oxygen vacancies on surface of the photocatalyst. To sum up, the defective (001)-TiO 2 -x/h-BN composite can be considered as a promising material for environmental applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）