排序方式: 共有80条查询结果,搜索用时 15 毫秒
1.
A systematic quantum chemical characterization of intrinsic structure, energies and spectral properties of all the studied cross-link adducts formed by the novel trans platinum with thiazole ligand has been carried out at B3LYP/6-31G^* level of theory with the Lanl2dz pseudo potential basis set for the Pt atom. Special attention has been paid to the relative stability of these complexes and the factors that probably alter the order of the relative stability. The important influence of hydrogen bond on the structures, the energies and the spectral property was revealed. Other factors that contribute to relative stability including solvation effect, entropy and electronic delocalization energy were taken into account. The stability energy of the whole complex, and the interaction energy between two purine bases and the [Pt-(NH3)thiazole]^2+ group were adopted to study the interplay among subsystems and their contribution to relative stability of all the studied cross-link model. Finally, basic spectral properties of these complexes including H(8) chemical shifts of all the studied complexes and the VCD (vibrational circular dichroism) spectra of two pairs of GG chelate enantiomers, were provided in order to define the structure of the most possible duplex bearing novel trans platinum drug lesions. 相似文献
2.
3,4—二硫方酸的从头算研究 总被引:2,自引:2,他引:2
在6-31G°水平上对3,4-二硫方酸(3,4-二巯基-3-环丁烯-1,2-二酮)的3种平面构象异构体进行SCF计算,结果表明,ZZ型异构体最稳定,XE型次之,从等键反应能量分析,3,4-二太酸的稳定性,与苯作探讨其芳香性,关在6-31G水平上计算了3种构象的振动频率。 相似文献
3.
4.
5.
6.
MgO缺陷和不规则表面吸附Cl2的电子结构研究 总被引:2,自引:0,他引:2
采用从头算程序对MgO表面 3种不同配位位置吸附Cl2 的构型进行优化 ,并用扩展休克尔紧束缚 (EHT)晶体轨道方法对MgO的缺陷和不规则表面吸附Cl2的可能构型进行能带计算 ,讨论了吸附前后能带组成和成键性质的变化。研究表明 :MgO表面吸附Cl2 将更趋向于吸附在O原子上而非Mg原子上 ,而且在 3种配位中MgO表面三配位氧最有利于吸附Cl2 ;吸附时 ,电子从O原子转移到Cl2 分子的反键轨道 ,但是各种吸附构型的MgO表面对Cl2 的吸附作用均比较微弱 ,是典型的物理吸附。 相似文献
7.
以小论文进行有机化学考试的尝试 总被引:3,自引:0,他引:3
本科三年级有机化学以写小论文进行考试 ,提供了操作的雏形。试验表明 ,有利于培养学生的综合能力及科学素质 ,作法可行 相似文献
8.
在密度泛函B3LYP/6-31G*水平上,对新型反式噻唑铂抗癌药物形成的DNA交联双功能加合物的结构、能量、光谱性质进行系统的量化表征,计算中Pt2+用LanL2DZ赝势基组。详细考察了这些加合物的相对稳定性顺序及其主要的影响因素。研究发现氢键对加合物的几何构型、能量、光谱性质均有很大的影响。其它影响因素如溶剂化,熵和电子离域能对相对能级的改变也起了一定的作用。本文采用化合物整体稳定化能,两个嘌呤碱基与[Pt-(NH3)thiazole]2+ 部分的相互作用能来研究不同部分间的相互作用及其对加合物的相对稳定性的影响。最后,为了确定最有可能含有这类反铂药物的DNA双螺旋的结构,本文给出加合物的H(8) 的化学位移和两对GG鳌合物的园二色光谱图作为参考。 相似文献
9.
In the present work, the hydrolysis process of non-classical transplatin(Ⅱ) with two same planar heterocycle amines has been studied using hybrid density functional theory (B3LYP) and IEF-PCM solvation models. Optimizations were performed at the B3LYP level using a combined basis set of (LanL2DZ+6-31 +G(d,p)) with single-point energy evaluations using the B3LYP/6-31 + +G(3df,2pd) approach in vacuo and in aqueous solution. For the obtained structures of reactants, intermediates, transition states, and products, both thermodynamic (reaction energies and Gibbs energies) and kinetic (reaction barriers) characteristics were estimated. In comparison with cisplatin, decreased activation energies were obtained. The result implies that the non-classical transplatin with two same planar heterocycle amines increases the equatorial steric effect and lowers reaction barriers, which may assist in designing novel Pt-based anticancer drugs. 相似文献
10.