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Quantum chemical and topological study on the insertion reaction of dichlorcarbene with acetaldehyde

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Chinese Science Bulletin 2008年第15期53卷 2287-2296页

作者： LI ZhiFeng zhu yuancheng YANG Sheng LU XiaoQuan College of Life Science and Chemistry Tianshui Normal University Tianshui 741001 China Gansu Key Laboratory of Polymer Materials College of Chemistry and Chemical Engineering Northwest Normal University Lan- zhou 730070 China

The insertion reaction mechanisms of siglet and striglet CCl2 with CH3CHO have been studied by using the DFT, NBO, CCSD(T) and AIM method. The geometries of reactions, transition state and products were completely optimized by B3LYP/6-31G(d). All the energy of the species was obtained at the CCSD(T)/6-31G(d,p) level. The calculated results indicated that all the major pathways of the reaction were obtained on the singlet potential energy surface. The singlet CCl2 can not only insert the Cα—H (reaction I) but also can react with Cβ—H (reaction Ⅱ). There are three main existing pathways and the products are P1 (CH3COHCCl2), P2 (CH2COHCHCl2) and P4[CHCl2CHCHOH] respectively. Reaction Ⅱ happens more easily according to the energy changes and the barrier in rate-controlling step. In addi-tion, the important geometries in domain pathways have been studied by AIM theory. And also, the en-ergy changes of H in the inserted C—H bond have been investigated.

关键词：量子化学插入反应 CCl2 DFT NBO

Quantum chemical study on insertion and abstraction reaction of dichlorocarbene with methyl alcohol and methyl mercaptan

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Science China Chemistry 2009年第3期52卷 304-312页

作者： LI ZhiFeng zhu yuancheng LI HuiXue LIU XinWen LU XiaoQuan College of Life Science and Chemistry Tianshui Normal UniversityTianshui 741001China Key Laboratory of Polymer Materials of Gansu Province College of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou 730070China

The insertion and abstraction reaction mechanisms of singlet and triplet CCl2 with CH3MH (M=O, S) have been studied by using the DFT, NBO and AIM methods. The geometries of reactions, the transition state and products were completely optimized by B3LYP/6-311G(d, p). All the energy of the species was obtained at the CCSD(T)/6-311G(d, p) level. The calculated results indicated that the major pathways of the reaction were obtained on the singlet potential energy surface. The singlet CCl2 can not only trigger the insertion reaction with C-H and M-H in four pathways, by which the products P1 [CH3OCHCl2, reactionⅠ(1)], P3[Cl2HCCH2OH, reactionⅠ(2)], P5[CH3SCHCl2, reactionⅡ(1)] and P7[Cl2HCCH2SH, reac-tion Ⅱ(2)] are produced respectively, but also abstract M-H, resulting P4 [CH2O+CH2Cl2, reactionⅠ(3)] and P8[CH2S+CH2Cl2, reactionⅡ(3)]. In addition, the important geometries in domain pathways have been studied by AIM and NBO theories.

关键词： carbene alcohol DFT NBO AIM insertion reaction abstraction reaction

Theoretical study of spin-orbit coupling and intersystem crossing in the two-state reaction between Nb(NH_2)_3 and N_2O

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Science China Chemistry 2012年第1期55卷 158-166页

作者： LV LingLing WANG XiaoFang zhu yuancheng LIU XinWen WANG-YongCheng College of Life Science and Chemistry Tianshui Normal UniversityTianshui 741001China College of Chemistry and Chemical Engineering Northwest Normal UniversityLanzhou 730070China

The two-state mechanism of the reaction of Nb(NH2)3 with N2O on the singlet and triplet potential energy surfaces has been investigated at the B3LYP *** points between the potential energy surfaces have been located using different *** of the strain model shows that the singlet state of the four-coordinate(N2O)Nb(NH2)3 complex with N2O bonded via terminal N atom coordination(12) is more stable in the initial stage of reaction,since the bending of the N2O fragment [Edef(N2O) = 86.1 kcal mol-1] results in an energy splitting of the doubly degenerate LUMO;the low-energy LUMO can now strongly couple with the occupied Nb-localized d orbitals,forming a back-bond and transferring charge(q = 0.82 e) from Nb(NH2)3 to the N2O *** from 32 to 12,the reacting system changes spin multiplicity near the MECP(minimal energy crossing point) region,which takes place with a spin crossing barrier of 9.6-10.0 kcal *** of spin-orbit coupling(SOC) indicates that MECP will produce a significant SOC matrix *** value of SOC is 111.52 cm-1,due to the electron shift between two perpendicular φ orbitals with the same rotation direction,and the magnitude of the spin-multi-plicity mixing increases in the small energy gap between high-and low-spin states,greatly enhancing the probability of intersystem *** probabilities of single(P1 ISC) and double(P2 ISC) passes estimated at MECP(SOC = 111.52 cm-1) are approximately 1.17×10-2 and 2.32×10-2,respectively.

关键词：反应势能面自旋交叉 d轨道耦合系统铌氧化亚氮 LUMO B3LYP

Theoretical study of spin-orbit coupling and zero-field splitting in the spin-forbidden two-state reaction between cobaltacyclopentadiene and isocyanate

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Chinese Science Bulletin 2014年第3期59卷 286-296页

作者： Lingling L Xiaofang Wang yuancheng zhu Xinwen Liu Kun Yuan Yongcheng Wang College of Life Science and Chemistry Tianshui Normal University College of Chemistry and Chemical Engineering Northwest Normal University

The two-state reaction mechanism of CpCo(C_4H_4)with isocyanate on the triplet and singlet potential energy surfaces has been investigated at the B3LYP level.A study is described for the computation of spin-orbit coupling of triplet state of the minimal energy crossing point(CP)with their singlet states and of the zerofield splitting(ZFS)parameters of the triplet states,including the full one-and two-electron terms of the BreitPauli *** are two key crossing points along this two-state reaction *** first crossing point—CP2 exists near^*** reacting system will change its spin multiplicity from the triplet state to the singlet state near this crossing *** the spin-orbit coupling interaction and ZFS D-tensor of the CP2 region are very strong,the reaction system will occur the reverse intersystem crossing from T_1 to S_***,its spin-flip efficiency may be *** second crossing point,CP3will again change its spin multiplicity from the singlet state to the triplet state in the Co-Cr bond activation pathway,leading to a decrease in the barrier height of^1TS(CF)from19.5 to 9.5 kcal/mol(1cal=4.182 J),and the efficiency of intersystem crossing from S_0 to T_1 is high because the larger spin-orbit coupling(SOC)matrix elements will result in the overpopulations of the three sublevels of T_1(3.30×10^(-1),3.32×10^(-1),and 3.38×10^(-1),respectively).

关键词：轨道耦合异氰酸酯零场分裂反应机理自旋 B3LYP 三重态交叉点

Theoretical characterization of single-electron iodine-bond weak interactions in CH_3…I-Y(Y=BH_2,H,CH_3,C_2H_3,C_2H,CN,NC)systems

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Chinese Science Bulletin 2012年第4期57卷 328-335页

作者： YUAN Kun LIU YanZhi zhu yuancheng ZUO GuoFang LUE LingLing LI ZhiFeng College of Life-science and Chemistry Tianshui Normal UniversityTianshui 741001China Key Laboratory for New Molecular Materials Design and Function of Gansu Education Department Tianshui 741001China

Iodine-involved single-electron halogen bonds (SEXBs) weak interactions in the systems of CH3···I-Y(Y = BH2, H, CH3, CH==CH2, C≡CH, CN, NC) were investigated for the first time using B3LYP/6-311++G(d,p) and MP2/aug-cc-pVTZ computational levels (the relativistic effective core potential basis set of Lanl2dz was used on iodine atom). The interaction energies between two moieties with basis set super-position error corrections for the seven complexes are -0.57, -1.36, -3.80, -2.17, -4.49,-6.33 and -8.64 kJ mol-1 (MP2/aug-cc-pVTZ ), respectively, which shows that SEXBs interactions are all weak. Natural bond orbital theory analysis revealed that charges flow from CH3 to the I-Y moiety. The total amount of natural bond orbital charge transfer (ΔNC) from the CH3 radical to I-Y increases in the order CH3…IBH2 < CH3…IH ≈ CH3…ICH3 ≈ CH3···IC2H3 < CH3…ICCH< CH3…ICN< CH3…INC. Atoms-in-molecules theory was used to investigate the topological properties of the bond critical points in the seven SEXB structures.

关键词： CH3自由基弱相互作用碘原子单电子债券 C2H3 点数系统

Theoretical study of the charge carrier mobilities of the molecular materials tetrathiafulvalene (TTF) and 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene (BDH-TTP)

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Science China Chemistry 2012年第10期55卷 2176-2185页

作者： LI HuiXue WANG XiaoFeng LI ZhiFeng ZHENG RenHui zhu yuancheng College of Life Science and Chemistry Tianshui Normal UniversityTianshui 741001China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of SciencesBeijing 100190China

Tetrathiafulvalene (TTF) is a kind of fused ring aromatic compound containing four sulfur atoms in one molecule, which is well known as a charge transport material. In order to calculate the charge mobility of this semiconductor, Marcus electron transfer theory and the embedded model, which can give small intramolecular reorganization energies, were employed. The calculated results were in good agreement with the experimental values, so the above computing model is appropriate to assess the electrical property of TTF. On this basis, we predicted the charge mobility of 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene (BDH-TTP) crystals, for which the molecular structure is similar to TTF. The calculated results indicated that BDH-TTP is a p-type material, which has a better performance than TTF in hole transfer due to larger hole coupling and the smaller hole injection barrier. In addition, the direct coupling (DC) and the site energy correction (SEC) methods were used to calculate the charge transfer integrals. Although the results were slightly different, the qualitative trends were the same. Furthermore we took into account the anisotropic transfer properties of TTF and BDH-TTF, since obviously the mobilities along one dimension are larger than those along three dimensions. Finally, natural bond orbital analysis was used to study the interactions in all of the dimers.

关键词：载流子迁移率四硫富瓦烯高分子材料电荷转移 TTF 自然键轨道分析计算结果芳香族化合物

Theoretical characterization of electronic structures and properties of C-F···H-C pseudohydrogen bonds

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Chinese Science Bulletin 2012年第16期57卷 1964-1971页

作者： YUAN Kun LIU YanZhi LU LingLing ZUO GuoFang zhu yuancheng DONG XiaoNing College of Life-science and Chemistry Tianshui Normal UniversityTianshui 741001China Key Laboratory for New Molecular Materials Design and Function of Gansu Education Department Tianshui 741001China

The weak intermolecular interactions between 2-F-tetrahydrofuran and imidazole, pyrimidine, adenine, and guanine were studied theoretically using density functional B3LYP/6-311++G** and HF/6-311++G** methods. The results showed that both conven- tional N···H hydrogen bond and C-F···H-C pseudohydrogen bond (PHB) structures coexist in the four complexes. The weak intermolecular interaction energies indicate that the relative stabilities of the four complexes are in the order guanine···F > imidazole···F > adenine···F > pyrimidine···F. The characteristics of the four PHBs were determined using geometry optimizations, stretching vibrational frequencies, and natural bond orbital and electron density topological properties calculations. The most important result is that the F group of 2-F-tetrahydrofuran can activate the C-H to accept electrons from another molecule, and C-F···H-C PHB formation is relatively favorable.

关键词：电子结构 CF 分子间弱相互作用债券表征属性伸缩振动频率四氢呋喃

Biomimetic fluorapatite films for conservation of historic calcareous stones

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Chinese Science Bulletin 2012年第13期57卷 1590-1594页

作者： YANG FuWei LIU Yan ZUO GuoFang zhu yuancheng ZHANG BingJian HUA PingNing Key Laboratory for New Molecule Material Design and Function Tianshui Normal UniversityTianshui 741000China Department of Cultural Heritage and Museology Zhejiang UniversityHangzhou 310027China Maijishan Grottoes Art Research Institute Tianshui 741000China

Fluorapatite protective films were prepared on marble substrates using a biomimetic method. By mimicking the mineralization mechanism of enamel, phosphorus and fluorine were introduced on the surface of the marble substrate. In the presence of a biological template, namely collagen, an integrated fluorapatite film was produced and the marble substrate was entirely covered. The prepared fluorapatite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The performances of the fluorapatite films were evaluated by color changes, capillary water absorption, and acid resistance tests. The results revealed that the fluorapatite films had good compatibility with the marble substrate; the physical properties such as color and capillary water adsorption of the marble substrates were unchanged. The fluorapatite films also had good acid resistance and were stable even in heavy acid rain.

关键词：薄膜生产磷灰石仿生保护石灰质扫描电子显微镜 X射线衍射历史

Beyond 600G fiber-THz wireless seamless integration system employing cascaded MIMO equalizers

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Science China(Technological Sciences) 2024年第7期67卷 2274-2276页

作者： DING JunJie TONG WeiDong LI XinTong ZHANG Zheng ZHANG Jiao CAI yuancheng LEI MingZheng HUA BingChang CHEN XingYu YU JianJun zhu Min Purple Mountain Laboratories Nanjing 211111China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China Fudan University Shanghai 200433China

Terahertz(THz)-wave communication, with sufficient spectrum resources(0.3 THz~10 THz), can meet the needs of future 6G large-capacity mobile communication services[1-9]. Recently, the seamless integration of existing ... 详细信息

关键词： communication fiber wireless

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