The molecular structure of cyclohexanone was calculated by the B3LYP density functional model with 6-31G(d,p)and 6-311++G(d,p)basis set by Gaussian program.The results from natural bond orbital(NBO)analysis have been ...The molecular structure of cyclohexanone was calculated by the B3LYP density functional model with 6-31G(d,p)and 6-311++G(d,p)basis set by Gaussian program.The results from natural bond orbital(NBO)analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title molecule.The electron density based local reactivity descriptors such as Fukui functions were calculated.The dipole moment(μ)and polarizability(α),anisotropy polarizability(Δα)and first order hyperpolarizability(βtot)of the molecule have been reported.Thermodynamic properties of the title compound were calculated at different temperatures.展开更多
在B3LYP/6-311++G(d,p)水平对白藜芦醇顺反异构体及第一三重激发态进行了结构优化、频率计算和自然键轨道(Natural Bond Orbital,NBO)分析.在MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)水平比较了白藜芦醇顺反异构体的能量.反式白藜芦醇...在B3LYP/6-311++G(d,p)水平对白藜芦醇顺反异构体及第一三重激发态进行了结构优化、频率计算和自然键轨道(Natural Bond Orbital,NBO)分析.在MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)水平比较了白藜芦醇顺反异构体的能量.反式白藜芦醇整个分子呈平面结构,顺式白藜芦醇两苯环之间存在约30o扭角.第一三重激发态中两苯环几乎处于互相垂直的关系,C7-H5与C8-H6键也是几乎互相垂直的关系.顺式和反式白藜芦醇C7-C8的σ键成键情况分别为sp1.53-sp1.53和sp1.59-sp1.60,C7与C8各自提供p轨道形成π键,即形成C7=C8双键.三重态中,C7-C8的成键情况为sp1.92-sp1.89,没有p-pπ键,C7、C8均还有一个2p轨道未参与杂化,NBO分析证实C7、C8的各自剩下的2p轨道均几乎独立形成了高能量的反键轨道,分别垂直于单羟基和双羟基苯环,C7-C8键长明显长于白藜芦醇顺反异构体.顺式白藜芦醇比反式白藜芦醇的自由能高约1.3-2.5 kcal/mol,反式构型是热力学稳定构型.含时密度泛函方法(Time-Dependent Density Functional Theory,TD-DFT)方法,B3LYP/6-311++G(d,p)水平计算得反式和顺式白藜芦醇最强紫外吸收峰分别在330 nm和319 nm.展开更多
在密度泛函(DFT)B3LYP/6-311++G^(**)水平下,求得4-氨基-3,5-二硝基吡唑(LLM-116)二聚体势能面上的4种全优化几何构型.经基组叠加误差(BSSE)和零点能(ZPE)校正,求得分子间最大相互作用能为-29.56 k J·mol^(-1).研究表明,其相互作...在密度泛函(DFT)B3LYP/6-311++G^(**)水平下,求得4-氨基-3,5-二硝基吡唑(LLM-116)二聚体势能面上的4种全优化几何构型.经基组叠加误差(BSSE)和零点能(ZPE)校正,求得分子间最大相互作用能为-29.56 k J·mol^(-1).研究表明,其相互作用是放热过程,并随着温度的升高,相互作用减弱;自然键轨道(NBO)分析揭示了相互作用的本质;对优化构型进行振动分析,得其红外光谱,并基于统计热力学求得200.0-800.0 K温度范围从单分子形成二聚体的热力学性质变化.展开更多
文摘The molecular structure of cyclohexanone was calculated by the B3LYP density functional model with 6-31G(d,p)and 6-311++G(d,p)basis set by Gaussian program.The results from natural bond orbital(NBO)analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title molecule.The electron density based local reactivity descriptors such as Fukui functions were calculated.The dipole moment(μ)and polarizability(α),anisotropy polarizability(Δα)and first order hyperpolarizability(βtot)of the molecule have been reported.Thermodynamic properties of the title compound were calculated at different temperatures.
基金supported by the National Natural Science Foundation of China(10804027,11011140321)Natural Science Foundation of Education Department of Henan Province,China(2011A140003)~~
文摘在B3LYP/6-311++G(d,p)水平对白藜芦醇顺反异构体及第一三重激发态进行了结构优化、频率计算和自然键轨道(Natural Bond Orbital,NBO)分析.在MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)水平比较了白藜芦醇顺反异构体的能量.反式白藜芦醇整个分子呈平面结构,顺式白藜芦醇两苯环之间存在约30o扭角.第一三重激发态中两苯环几乎处于互相垂直的关系,C7-H5与C8-H6键也是几乎互相垂直的关系.顺式和反式白藜芦醇C7-C8的σ键成键情况分别为sp1.53-sp1.53和sp1.59-sp1.60,C7与C8各自提供p轨道形成π键,即形成C7=C8双键.三重态中,C7-C8的成键情况为sp1.92-sp1.89,没有p-pπ键,C7、C8均还有一个2p轨道未参与杂化,NBO分析证实C7、C8的各自剩下的2p轨道均几乎独立形成了高能量的反键轨道,分别垂直于单羟基和双羟基苯环,C7-C8键长明显长于白藜芦醇顺反异构体.顺式白藜芦醇比反式白藜芦醇的自由能高约1.3-2.5 kcal/mol,反式构型是热力学稳定构型.含时密度泛函方法(Time-Dependent Density Functional Theory,TD-DFT)方法,B3LYP/6-311++G(d,p)水平计算得反式和顺式白藜芦醇最强紫外吸收峰分别在330 nm和319 nm.
文摘在密度泛函(DFT)B3LYP/6-311++G^(**)水平下,求得4-氨基-3,5-二硝基吡唑(LLM-116)二聚体势能面上的4种全优化几何构型.经基组叠加误差(BSSE)和零点能(ZPE)校正,求得分子间最大相互作用能为-29.56 k J·mol^(-1).研究表明,其相互作用是放热过程,并随着温度的升高,相互作用减弱;自然键轨道(NBO)分析揭示了相互作用的本质;对优化构型进行振动分析,得其红外光谱,并基于统计热力学求得200.0-800.0 K温度范围从单分子形成二聚体的热力学性质变化.
