期刊文献+
共找到71篇文章
< 1 2 4 >
每页显示 20 50 100
A review on nitrogen transformation and conversion during coal pyrolysis and combustion based on quantum chemical calculation and experimental study 被引量:7
1
作者 Tingting Jiao Huiling Fan +6 位作者 Shoujun Liu Song Yang Wenguang Du Pengzheng Shi Chao Yang Yeshuang Wang Ju Shangguan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第7期107-123,共17页
The emission of NOx during coal combustion contributes to the formation of acid rain and photochemical smog,which would seriously affect the quality of atmospheric environment.Therefore,the decrease of NOx is of great... The emission of NOx during coal combustion contributes to the formation of acid rain and photochemical smog,which would seriously affect the quality of atmospheric environment.Therefore,the decrease of NOx is of great importance for improving the efficient utilization of coal.The present review comprehensively summarized the influence factors and mechanisms of migration and transformation of nitrogen during the coal pyrolysis and combustion based on experimental study and quantum chemical calculation.Firstly,in the process of pyrolysis:the occurrence state and transformation of nitrogen were concluded.The influence of temperature,atmosphere,heating rate and catalyst on formation of NOx precursor and nitrogen migration path at the molecular level were summarized;Secondly,during the process of combustion:the influence of temperature,ambient oxygen concentration,physical structure of coal char,catalyst on heterogeneous oxidation of char(N)were summarized;The effects of char surface properties,catalyst and ambient atmosphere on heterogeneous reduction of NOx were also concluded.Based on the quantum chemical calculation,the reaction path of heterogeneous oxidation of char-N and heterogeneous reduction of NOx were described in detail.Current studies focus more on the generation of HCN and NH3,but in order to reduce the pollution of NOx from the source,it is necessary to further improve the process conditions and the optimal formula of producing more N2 during pyrolysis,as well as clarify the path of the generation of N2.Experiments study and quantum chemistry calculation should be combined to complete the research of directional nitrogen reduction during pyrolysis and denitration during combustion. 展开更多
关键词 Coal combustion PYROLYSIS ENVIRONMENT Nitrogen oxides quantum chemical calculation
在线阅读 下载PDF
Raman spectroscopy and quantum chemical calculation on YCl_(3)-KCl molten salt system 被引量:3
2
作者 Can Xu Xian-Wei Hu +5 位作者 Jiang-Yu Yu Peng-Wei Li Ai-Min Liu Shao-Hua Luo Zhong-Ning Shi Zhao-Wen Wang 《Rare Metals》 SCIE EI CAS CSCD 2023年第11期3886-3896,共11页
The knowledge on the ionic structure of YCl_(3)-KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrol... The knowledge on the ionic structure of YCl_(3)-KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrolyte.In this paper,the theoretical Raman spectra of the ionic groups which may exist in YCl_(3)-KCl molten system are simulated by quantum chemical calculation using Gaussian09 and Gauss View 5.0 programs based on density functional theory(DFT).Then the ionic structures of 20 mol%-60 mol%YCl_(3)-KCl molten salt systems are studied by comparing the Raman shift values of the bands in the theoretical Raman spectra of different ionic groups with the experimental spectra of this system.YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)are thought to exist in the molten system.With the increase of temperature,the relative content of YCl_(6)^(3-)ionic groups increases while those of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)ionic groups decrease.Moreover,the"lifetime"of all ionic groups decreases within the temperature range of 692-730℃.Meanwhile,the relative contents of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)increase with the increase of YCl_(3)content,while that of YCl_(6)^(3-)decreases.The wave function analysis of the four ionic groups(YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-),and Y_(2)Cl_(9)^(3-))is carried out by Multiwfn program.The net charge in each group,the direction of electron migration during the formation of each group,the sites where electrophilic and nucleophilic reactions are most likely to occur in each ionic group,and the order of bond breaking during chemical reactions for the four groups are obtained. 展开更多
关键词 YCl_(3)-KCl molten salt Ionic structure Raman spectroscopy quantum chemical calculation Wave function analysis
原文传递
Hydrothermal Synthesis,Crystal Structure,Spectrum Properties and Quantum Chemical Calculation of a Trinuclear Copper(Ⅱ) Complex with 3-(Pyridin-2-yl)-1,2,4-triazole 被引量:1
3
作者 李昶红 李薇 +1 位作者 李玉林 杨颖群 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第8期1089-1094,共6页
A three-dimensional framework copper(Ⅱ) coordination polymer with copper carbonate basic and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) has been hydrothemally synthesized.The complex (2,C14 H10 CuN8 ·3H2 O) c... A three-dimensional framework copper(Ⅱ) coordination polymer with copper carbonate basic and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) has been hydrothemally synthesized.The complex (2,C14 H10 CuN8 ·3H2 O) crystallizes in tetragonal,space group P4 2 /n,a=2.08581(12),b=2.08581(12),c=0.72331(4) nm,M r=761.73,V=3.1468(3) nm 3,Dc=1.608 g/cm 3,Z=4,F(000)=1552,GOOF=1.07,R=0.0515 and wR=0.1689.Every asymmetric unit molecular structure of the complex is composed with one copper ion,one and half water molecules and two Hpt molecules.Each copper ion is coordinated with five nitrogen atoms from four Hpt molecules,forming a distorted square pyramidal geometry.The fluorescence spectrum analysis shows that the title complex at room temperature exhibits intense photoluminescence with maximum emission at 450 nm.The quantum chemistry calculation study on the complex has been performed.The stability,some frontier molecular orbital energies and composition characteristics of some frontier molecular orbitals of the complex have been investigated. 展开更多
关键词 trinuclear copper complex hydrothermal synthesis spectrum properties quantum chemical calculation
在线阅读 下载PDF
QUANTUM CHEMICAL CALCULATIONS ON THE ELECTRONIC STRUCTURE AND SPECTRA OF[Mo_3O_4-nSn]^(4+)(n=O-4)CLUSTER CATIONS
4
作者 Zhi Ru LI Qian Shu LI Ji Kang FANG Zhi Ren ZHENG Jun ZHENG Department of Chemistry,Jilin University,Changchun,130023 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第1期43-46,共4页
The electronic structure and spectra of [Mo3O4-nSn]^(4+)(n=0-4) cations were calculated by means of INDO/CI quantum chemistry method to account for the experimental data of their spectra in water solutions.
关键词 HOMO n=O-4)CLUSTER CATIONS Ho LUMO N quantum chemical calculationS ON THE ELECTRONIC STRUCTURE AND SPECTRA OF[Mo3O4-nSn MO
在线阅读 下载PDF
Formation and dissociation of protonated cytosine–cytosine base pairs in i-motifs by ab initio quantum chemical calculations
5
作者 张小虎 黎明 +1 位作者 王延颋 欧阳钟灿 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第2期189-192,共4页
Formation and dissociation mechanisms of C-C+ base pairs in acidic and alkaline environments are investigated, employing ab initio quantum chemical calculations. Our calculations suggest that, in an acidic environmen... Formation and dissociation mechanisms of C-C+ base pairs in acidic and alkaline environments are investigated, employing ab initio quantum chemical calculations. Our calculations suggest that, in an acidic environment, a cytosine monomer is first protonated and then dimerized with an unprotonated cytosine monomer to form a C-C+ base pair; in an alkaline environment, a protonated cytosine dimer is first unprotonated and then dissociated into two cytosine monomers. In addition, the force for detaching a C-C+ base pair was found to be inversely proportional to the distance between the two cytosine monomers. These results provide a microscopic mechanism to qualitatively explain the experimentally observed reversible formation and dissociation of i-motifs. 展开更多
关键词 ab initio quantum chemical calculation I-MOTIF protonated cytosine-cytosine base pair
原文传递
Quantum Chemical Calculations of the Structure,Property and Stability of Penta-coordinated Carbonium Ions Derived from Normal Butane
6
作者 Tao Haiqiao Long Jun +3 位作者 Zhou Han Xie Chaogang Dai Zhenyu Wei Xiaoli 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2009年第2期27-30,共4页
The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the ... The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the following order: C2HC3〈C1HC2〈C2HH〈C1HH, and the stability decreases in the following order C2HC3〉C1HC2〉C2HH〉C1HH. The stability of the penta-coordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-coordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated earbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds. 展开更多
关键词 N-BUTANE penta-coordinated carbonium ions STRUCTURE quantum chemical calculation
在线阅读 下载PDF
A Polymer {[Cu^Ⅱ(Hpb)(mal)]H=O}n: Magnetic Studies and Quantum Chemical Calculation for Its Monomer 被引量:1
7
作者 朱海燕 周利君 +2 位作者 王尧宇 文振翼 王育彬 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2006年第3期321-325,共5页
{[Cu^Ⅱ(Hpb)(mal)]H=O}n (Hpb=2-2'-pyridylbenzimidazole, mal=maleic acid) is a helical chain-like polymer complex. In order to investigate the electronic structure of the complex, the monomer Cu^Ⅱ(Hpb)(mal)... {[Cu^Ⅱ(Hpb)(mal)]H=O}n (Hpb=2-2'-pyridylbenzimidazole, mal=maleic acid) is a helical chain-like polymer complex. In order to investigate the electronic structure of the complex, the monomer Cu^Ⅱ(Hpb)(mal) was obturated with different functional groups respectively. For these selective segments, the geometry optimizations were conducted by using hybrid DFT (B3LYP)methods to find that the structure obturated with H2O was better consistent with the experiment, and then this model would be used to latter calculations, such as the frontier molecular orbital and the NBO charge population analysis. In addition the magnetic behaviors of this complex were analyzed by experiments and the weak antiferromagnetic couple between copper(Ⅱ) ions was observed. The exchange coupling constant was calculated by DFT based on the spin broken symmetry formalism. The calculated coupling constants were in good agreement with the experimental data. 展开更多
关键词 POLYMER MAGNETIC quantum chemical calculation natural bond orbital
原文传递
THE MASS SPECTRA OF AROMATIC CONJUGATED POLYENIC ACID,METHYL BENZOATE,METHYL PHENYL KETONE,BENZONITRILE AND ANILINE AND THEIR QUANTUM CHEMICAL CALCULATIONS
8
作者 赖柱根 梁德声 房耀仁 《Science China Chemistry》 SCIE EI CAS 1982年第10期1035-1043,共9页
A quantitative interpretation of mass spectra of complex organic compounds so far is notvery perfect and needs some further investigation. In this paper a mechanism of cleft-rate-determining-steps of aromatic conjugat... A quantitative interpretation of mass spectra of complex organic compounds so far is notvery perfect and needs some further investigation. In this paper a mechanism of cleft-rate-determining-steps of aromatic conjugated polyenic acid, methyl benzoate, methyl phenyl ketone,benzonitrile and aniline is proposed, and various quantum parameters of molecular ions ofaromatic conjugated polyenic compounds, together with their framents are calculated bymeans of CNDO/2 method. Through the process of calculation, the peak-height of mass spectracan be quantitatively interpreted, which means that the main factors which influence the cleftforms of simple cleavage of mass spectra of conjugated compounds given by the authorsmight be true to some extent. 展开更多
关键词 兀一 THE MASS SPECTRA OF AROMATIC CONJUGATED POLYENIC ACID METHYL BENZOATE METHYL PHENYL KETONE BENZONITRILE AND ANILINE AND THEIR quantum chemical calculationS CNDO
原文传递
Synthesis,Crystal Structure and Quantum Chemical Investigation of Bis-Schiff Base Compounds Derived from2-phenyl-1,2,3-triazole-4-carboxaldehyde with Diamine 被引量:2
9
作者 XIE Ling LIU Gang WANG Yan WANG Ji-De CHEN Jun-Feng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第5期616-621,共6页
Two new schiff base N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,3-propanediamine (1) and N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene) -1,4-butanediamine (2) were synthesized by condensat... Two new schiff base N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,3-propanediamine (1) and N,N'-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene) -1,4-butanediamine (2) were synthesized by condensation of 2-phenyl-1,2,3-triazole-4-carboxaldehyde with diamine, and characterized by elemental analysis, IR, IH NMR and MS spectra. Their crystal structures were determined by X-ray single crystal diffraction. Both crystals belong to the monoclinic system, space group P21/c. For compound 1(C21H20N8, Mr=384.45): a = 16.314(3), b =5.7168(11), c = 21.316(4) A, β = 105.3(2)°, Z = 4, V = 1917.6(7) A^3, De =1.332 g/cm^3, F(000) = 808,μ = 0.086 mm 1, R = 0.0533 and wR = 0.1460; for compound 2 (C22H22N8, Mr=398.48): a = 8.6156(17), b = 5.2964(11), c = 22.665(5)A, β = 100.54(3)°, Z = 2, V = 1016.8(4) A^3, De= 1.302 g/cm^3, F (000) = 420, μ = 0.083 mm^-1, R = 0.0373 and wR = 0.1155. Based on the crystal data, quantum chemistry calculation was performed on the two title compounds by means of Gaussian 98 program. The molecular orbital energies and atomic net charges population were obtained. Furthermore, we antilyzed their active atoms. The investigation can serve as a theoretical guide to study the synthesis and activity of the title compounds. 展开更多
关键词 schiff base crystal structure quantum chemical calculation
在线阅读 下载PDF
Synthesis, Crystal Structure,Characterization and Quantum Chemical Studies on 1N-Acetyl-3-(2,4-dichloro-5-fluoro- phenyl)-5-(p-methyl-phenyl)-2-pyrazoline
10
作者 郭焕美 张静 +1 位作者 赵朴素 建方方 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第12期1491-1498,共8页
1N-Acetyl-3-(2,4-dichloro-5-fluoro-phenyl)-5-(p-methyl-phenyl)-2-pyrazoline has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray single-crystal diffraction. Ab intio calculations have... 1N-Acetyl-3-(2,4-dichloro-5-fluoro-phenyl)-5-(p-methyl-phenyl)-2-pyrazoline has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray single-crystal diffraction. Ab intio calculations have been carded out for the compound by using both B3LYP and HF methods at the 6-31G^* basis set. The calculated results show that the predicted geometry can well reproduce the structural parameters. The electronic absorption spectra calculated by B3LYP/6-31G^* method are approximate to the experiments and the Natural Bond Orbital (NBO) analyses suggest that the above electronic transitions are mainly assigned to n→π^* and π→π^* transitions. CIS-HF/6-31G^* method is not suitable to predict the electronic spectra for the title compound. The calculation of the second order optical nonlinearity was carded out, giving the value of molecular hyperpolarizability equal to 2.194^+ 10^-30 esu. On the basis of vibrational analyses, the thermodynamic properties of the compound at different temperature have been calculated, revealing the correlation between C p, m^0, S m^0, H m^0 and temperature. 展开更多
关键词 SYNTHESIS crystal structure quantum chemical calculation electronic absorption spectra thermodynamic property
在线阅读 下载PDF
Synthesis, Structure and Quantum Mechanical Calculations of Methyl 2-(5-((Quinolin-8-yloxy)-methyl)-1,3,4-oxadiazol-2-ylthio)-acetate
11
作者 AAMER SAEED FOUZIA PERVEEN +2 位作者 NAEEM ABBAS SIDRA JAMAL ULRICH FL?RKE 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第6期858-870,共13页
The title compound was synthesized by the base catalyzed reaction of 5-((quinolin- 8-yloxy)methyl)-1,3,4-oxadiazole-2(3H)-thione with methyl chloroacetate. The structure was supported by the spectroscopic data a... The title compound was synthesized by the base catalyzed reaction of 5-((quinolin- 8-yloxy)methyl)-1,3,4-oxadiazole-2(3H)-thione with methyl chloroacetate. The structure was supported by the spectroscopic data and unambiguously confirmed by single-crystal X-ray diffraction studies. It crystallizes from a methanol solution in the triclinic space group Pi with unit cell dimensions a = 7.4509(9), b = 10.2389(12), c = 12.2299(15)A, a = 74.771(2), β = 77.956(2), 7 = 69.263(2)°, V = 834.98(17) A3 and Z = 2. In order to gain some valuable insights into the molecular structure, the quantum mechanical calculations were performed using both HF and time-dependent density functional theory at the B3LYP/6-31G(d,p) level. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional theory (DFT) with the 6-31G(d) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound was examined using the B3LYP method with the 6-31G(d) basis set. The harmonic vibrational frequencies calculated have been compared with the experimental FTIR and FT-Raman spectra. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of the title compound. Moreover, molecular electrostatic potential and thermodynamic parameters of the title compound were investigated by theoretical calculations. 展开更多
关键词 methyl 2-(5-((quinolin-8-yloxy)methyl)-1 3 4-oxadiazol-2-ylthio)acetate CRYSTALSTRUCTURE CONFORMER quantum chemical calculations vibrational studies
在线阅读 下载PDF
Syntheses,crystal structures,and quantum chemistry calculation of two Ni(Ⅱ)coordination polymers 被引量:2
12
作者 LI Xiumei HUANG Yanju +1 位作者 LIU Bo PAN Yaru 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第10期2031-2039,共9页
Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmeth... Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2. 展开更多
关键词 coordination polymer nickel(Ⅱ)complex crystal structure quantumchemical calculation
在线阅读 下载PDF
Sesquiterpenoids from Tussilago farfara: full structure elucidation, anti-diabetic and anti-inflammatory signaling pathways
13
作者 Hao Zheng Yang Li +6 位作者 Yujia Zhang Zhixuan Li Dongli Li Jucai Xu Jianjun Zhang Ligen Lin Lishe Gan 《Chinese Journal of Natural Medicines》 2026年第3期373-384,共12页
Four new sesquiterpenoids(1-4), including the first reported instance of a novel 2,3-seco oplopane carbon skeleton(1), together with 19 known analogues, were isolated from the flower buds of Tussilago farfara(coltsfoo... Four new sesquiterpenoids(1-4), including the first reported instance of a novel 2,3-seco oplopane carbon skeleton(1), together with 19 known analogues, were isolated from the flower buds of Tussilago farfara(coltsfoot). The challenging determination of relative and absolute configurations—particularly in flexible side chains and substituents—was achieved for the first time through an integrated approach combining spectroscopic analyses, chemical derivatization, chiral gas chromatography(GC), and quantum chemical calculations. All compounds were evaluated for anti-diabetic activity using an insulin-stimulated glucose uptake model in C2C12 myotubes and for anti-inflammatory activity via a lipopolysaccharide(LPS)-induced nitric oxide(NO) inhibition assay in RAW264.7 macrophages. Six compounds significantly enhanced glucose uptake, and mechanistic investigation of compound 3 revealed activation of the insulin receptor substrate 1(IRS-1)/protein kinase B(Akt)/glycogen synthase kinase 3β(GSK-3β) signaling pathway. Twenty-one compounds exhibited marked inhibition of NO production;among them, compounds 2 and 6 dose-dependently suppressed inducible nitric oxide synthase(iNOS) expression and nuclear factor κB(NF-κB) phosphorylation. 展开更多
关键词 SESQUITERPENOIDS quantum chemical calculations 2 3-seco Oplopane Tussilago farfara Anti-diabetes ANTI-INFLAMMATION
原文传递
Structural Evolution and Electronic Properties of Au2Gen-/0(n=1-8) Clusters: Anion Photoelectron Spectroscopy and Theoretical Calculations
14
作者 Sheng-Jie Lu Hong-Guang Xu +1 位作者 Xi-Ling Xu Wei-Jun Zheng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第2期229-240,I0003,共13页
Investigating the structures and properties of Au-Ge mixed clusters can give insight into the microscopic mechanisms in gold-catalyzed Ge films and can also provide valuable information for the production of germanium... Investigating the structures and properties of Au-Ge mixed clusters can give insight into the microscopic mechanisms in gold-catalyzed Ge films and can also provide valuable information for the production of germanium-based functional materials. In this work, size-selected anion photoelectron spectroscopy and theoretical calculations were used to explore the structural evolution and electronic properties of Au2Gen^-/0 (n=1-8) clusters. It is found that the two Au atoms in Au2Gen^-/0 (n=1-8) showed high coordination numbers and weak aurophilic interactions. The global minima of Au2Gen- anions and Au2Gen neutrals are in spin doublet and singlet states, respectively. Au2Gen- anions and Au2Gen neutrals showed similar structural features, except for Au2Ge4^-/0 and Au2Ge5^-/0. The C2v symmetric V-shaped structure is observed for Au2Ge1^-/0, while Au2Ge2^-/0 has a C2v symmetric dibridged structure. Au2Ge3^-/0 can be viewed as the two Au atoms attached to different Ge-Ge bonds of Ge3 triangle. Au2Ge4- has two Au atoms edge-capping Ge4 tetrahedron, while Au2Ge4 neutral adopts a C2v symmetric double Au atoms face-capping Ge4 rhombus. Au2Ge5-8^-/0 show triangular, tetragonal, and pentagonal prism-based geometries. Au2Ge6 adopts a C2v symmetric tetragonal prism structure and exhibits σ plus π double bonding characters. 展开更多
关键词 Photoelectron spectroscopy Transition metal Germanium cluster Structural evolution quantum chemical calculations
在线阅读 下载PDF
Synthesis, Characterization, Crystal Structure and Quantum Chemical Calculation of Novel Compound 1,3-Dimethyl-2-ferrocenylmethylbenzimidazolium Iodide 被引量:4
15
作者 张晶 杨秉勤 +2 位作者 朱海燕 李涛 文振翼 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2006年第5期637-641,共5页
A novel benzimidazole derivative, 1,3-dimethyl-2-ferrocenylmethylbenzimidazolium iodide (1) was synthesized and characterized by elemental analysis, MS, IH NMR and IR spectra. Its crystal structure was determined by... A novel benzimidazole derivative, 1,3-dimethyl-2-ferrocenylmethylbenzimidazolium iodide (1) was synthesized and characterized by elemental analysis, MS, IH NMR and IR spectra. Its crystal structure was determined by X-ray single crystal diffraction, and the title compound belongs to monoclinic system with space group P2(1)/c. According to the crystal structure, the quantum chemistry calculation was performed by Gaussian 03 program, and full geometry optimizations of the title compound were carried out with DFT method at B3LYP/6-31G level. Its structure, stability, frontier molecular orbital components and net charge distribution were discussed. 展开更多
关键词 1 3-dimethyl-2-ferrocenylmethylbenzimidazolium SYNTHESIS crystal structure quantum chemical calculation
原文传递
Structure and property evolution of atomically precise palladium clusters
16
作者 Chang-Qing Meng Wan-Yu Cheng +6 位作者 Hao Yan Hui-Xin Xiang Chen-Hao Ruan Yue Zhao Cong-Qiao Xu Jun Li Chuan-Hao Yao 《Rare Metals》 2025年第4期2822-2829,共8页
Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clus... Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond. 展开更多
关键词 structure evolution catalytic properties quantum chemical calculations cyclohexanethiol ligands electrospray ionization mass spectrometry esi ms atomically precise palladium clusters sonogashira cross coupling reactions electronic structure
原文传递
Dual-mode capacitive phosphate capture enabled by topologically confinement-engineered ZIF-derived NiCo-LDH heterojunctions
17
作者 Yubo Pan Ruijie Che +6 位作者 Keren Lu Linrui Li Mingxing Shi Hua Qiang Mingzhu Xia Fenghe Wang Fengyun Wang 《Journal of Energy Chemistry》 2025年第12期129-142,I0005,共15页
The escalating challenge of phosphorus pollution demands innovative solutions for efficient phosphate removal and recovery.Herein,a three-dimensional heterostructured C-ZIF@LDH/CF anode was constructed for capacitive ... The escalating challenge of phosphorus pollution demands innovative solutions for efficient phosphate removal and recovery.Herein,a three-dimensional heterostructured C-ZIF@LDH/CF anode was constructed for capacitive deionization(CDI)by in-situ growing NiCo-layered double hydroxide(LDH)nanoflowers on a carbonized Co-ZIF-L framework anchored onto carbon fiber cloth(CF).This architecture synergistically integrates hierarchical porosity,dual-mode capacitive mechanisms of electrical doublelayer and Faradaic pseudocapacitance,and robust interracial charge transfer pathways.Comprehensive physicochemical characterizations validated the morphological evolution and synergistic valence modulation of metallic species.Electrochemical evaluations revealed outstanding phosphate removal performance,achieving a record adsorption capacity of 34.96 cmp/g in 50 mg_P/L solution,along with superior kinetic efficiency(0.21 mgp/g/min)in hybrid CDI(HCDI)operation.The heterojunction design ensures 95.71%capacity retention over 50 cycles and exceptional selectivity against competing anions.Molecular dynamics(MD)simulations further validate the confinement effect of LDH layers,demonstrating preferential phosphate adsorption through hydrogen bonding and restricted ion mobility.Density functional theory(DFT)calculations elucidate that the ZIF-derived carbon framework enhances conductivity through Co-C hybridization,while simultaneously revealing a reduced work function and a significantly stronger phosphate adsorption energy compared to pristine NiCo-LDH,underpinning enhanced electron transfer and chemisorption.This work provides a paradigm for advanced CDI systems,bridging structural engineering with atomic-scale mechanistic insights to address water-energy-resource challenges. 展开更多
关键词 Phosphate removal Capacitive deionization Layered double hydroxides Hierarchical electrode materials quantum chemical calculations Molecular dynamics simulations
在线阅读 下载PDF
Formation of highly toxic p-benzoquinones byproducts during ozonation of cresols
18
作者 Weixu Tang Jianjian Wei +5 位作者 Shuting Wang Qiang Cheng Aroob Abid Jia Gu Min Zheng Dehua Ma 《Journal of Environmental Sciences》 2025年第8期495-508,共14页
This study aims to identify the highly non-specific toxic by-products during ozonation of three cresols in wastewater.In ozonated effluents,biotoxicity increased along with increasing reaction time,followed by a gradu... This study aims to identify the highly non-specific toxic by-products during ozonation of three cresols in wastewater.In ozonated effluents,biotoxicity increased along with increasing reaction time,followed by a gradual decrease.The peak biotoxicity for ozonated o-cresol(o-C),m-cresol(m-C),and p-cresol(p-C)was estimated to be 17.4,14.8 and 5.5 times higher than that of untreated wastewater,respectively.A redox-directed approach with high-resolution mass spectrometry detection and toxicity prediction revealed that monomeric para-benzoquinones(p-BQs),hydroxylated p-BQs,and dimeric p-BQs in ozonated cresols were the primary contributors to the increased toxicity.Calculations based on density functional theory indicated formation pathways of p-BQs byproducts,e.g.,the formation of 2-methyl-p-benzoquinone was likely induced by ozone molecules rather than hydroxyl radicals in ozonated o-C and m-C,and the formation of p-BQs during ozonation of p-C was attributed to the oxidation of methyl group to carboxyl group and subsequent decarboxylation initiated by hydroxyl radicals.Electron paramagnetic resonance and spin density calculation showed that the presence of carbon-centered cresoxyl radicals was responsible for dimeric p-BQs formation.Collectively,these results underscore significant contribution of non-halogenated p-BQs to non-specific toxicity increase in ozonated effluents. 展开更多
关键词 OZONATION CRESOLS Highly toxic byproducts P-BENZOQUINONES quantum chemical calculations
原文传递
Ligand-mediated reactivity in CO oxidation of yttrium-nickel monoxide carbonyl complexes
19
作者 Jumei Zhang Ziheng Zhang +3 位作者 Gang Li Hongjin Qiao Hua Xie Ling Jiang 《Chinese Chemical Letters》 2025年第2期151-155,共5页
A series of heteronuclear yttrium-nickel monoxide carbonyl complexes YNiO(CO)_(n)^(-)(n=1-5)were generated in a pulsed-laser vaporization source and characterized by mass-selected photoelectron velocity-map spectrosco... A series of heteronuclear yttrium-nickel monoxide carbonyl complexes YNiO(CO)_(n)^(-)(n=1-5)were generated in a pulsed-laser vaporization source and characterized by mass-selected photoelectron velocity-map spectroscopy combined with theoretical calculations.CO ligand-mediated reactivity in CO oxidation of yttrium-nickel monoxide carbonyl complexes was experimentally and theoretically identified.During the consecutive CO adsorption,aμ^(2)-O linear structure was most favorable for YNiO(CO)_(n)^(-)(n=1,2),then a structure in which the terminal O was bonded to the Y atom became favored for YNiO(CO)_(3)^(-),and finally a structure bearing a CO_(2)moiety was most favorable for YNiO(CO)_(n)^(-)(n=4,5).Theoretical calculations indicated that the Ni atom acted as an electron acceptor and accumulated electron density at n≤3,and then served as an electron donor along with the Y atom to contribute electron density in the rearrangement that accompanied CO oxidation at n>3. 展开更多
关键词 Heteronuclear cluster CO oxidation Electron donor quantum chemical calculation Photoelectron velocity-map imaging spectroscopy
原文传递
Separation of polycyclic aromatic hydrocarbons by solvent screening assisted extractive distillation from FCC diesel
20
作者 Jun Li Wanting Yu Jinsen Gao 《Chinese Journal of Chemical Engineering》 2025年第11期89-102,共14页
The oversupply of diesel in China necessitates efficient separation of polycyclic aromatic hydrocarbons from fluidized catalytic cracking diesel for value-added utilization.However,purification is hindered by alkane a... The oversupply of diesel in China necessitates efficient separation of polycyclic aromatic hydrocarbons from fluidized catalytic cracking diesel for value-added utilization.However,purification is hindered by alkane and monocyclic aromatic interference.In this work,we propose a solvent-screening strategy for extractive distillation based on molecular polarity and interaction energy analysis.Quantum chemical calculations identified ethylene glycol(aromatic solubility) and N,N-dimethylformamide(alkane selectivity) as optimal solvents,with weak hydrogen bonds(e.g.,O-H…π,C-H…π) governing aromatic interactions.Two process designs were developed:(1) solvent extraction followed by primary extractive distillation(purity >95.0%(mass)) and(2) direct two-stage extractive distillation(purity>92.0%(mass)).This work provides a flexible framework for polycyclic aromatic hydrocarbon separation tailored to market demands while elucidating solvent-solute interactions at the molecular level. 展开更多
关键词 Polycyclic aromatic hydrocarbons Extractive distillation Solvent screening quantum chemical calculation
在线阅读 下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部