磷酸二甲酯阴离子与二价金属离子相互作用的研究

在B3LYP/6-31G(d, p)水平上,用全电子分别研究了Mg2+、Ca2+、Mn2+、Co2+、Ni2+、Cu2+和Zn2+与磷酸二甲酯(DMP-)“双齿”配位模式下的相互作用,且由4个水分子((H2O)4)“饱和”各金属离子六配位模式下的其它位点。结果表明:这种配位模式下,DMP-对上述金属离子的选择性顺序为:Cu2+>Ni2+>Zn2+>Co2+>Mg2+>Mn2+>Ca2+,和Irving-Williams序列基本一致。且具有未充满d层轨道的金属对配体的变化“响应”明显。通过NBO(自然键轨道)方法对配合物电荷布居分析可得出主族金属离子与配体间以静电相互作用为主,非主族金属离子配合物中存在一定的共价作用的结论,同时关于配合物各部分间键轨道相互作用的分析部分的反映了金属离子与配体的作用实质。     

气相和溶液中金属离子与腺嘌呤配位选择性的理论研究

在B3LYP/6-31G(d,p)水平,全优化Mg2+、Ca2+、Mn2+、Co2+、Zn2+、Cu2+、Ni2+、Cd2+ (用有效实势(ECP) 方法处理)与腺嘌呤(A) N(1)、N(7)位点配位的两类配合物气相结构,通过相互作用能和自由能分析分别得出两位点对所研究金属离子的选择性顺序;后采用Onsager模型,优化其在水溶液(=78.39)中的结构,讨论溶剂效应对上述顺序的影响;通过相对自由能分析分别得出气相和溶液中,同种金属对两位点的选择性规律。溶液中金属离子与N(7)位配位的相对优选顺序为:Co2+ > Mg2+ > Cd2+ > Ca2+ > Zn2+ > Mn2+ > Ni2+ > Cu2+。     

磷酸二甲酯阴离子(DMP-)与一价、二价金属离子相互作用的理论研究

在B3LYP、HF和MP2水平上运用全电子从头算(AE)和相对论有效实势(RECP)及6-311+G**和LanL2DZ基组计算Ⅰa、Ⅰb、Ⅱa和Ⅱb族金属离子与磷酸二甲酯阴离子(DMP-)的相互作用。 RECP用于除Li+、Be2+外所有的金属离子。 对Na+、K+、Cu+、Mg2+、Ca2+、Zn2+用AE和RECP 2种方法处理。 结果表明:RECP能可靠地用于重金属离子络合物; 二价金属离子络合物(DMP-—M2+)比一价金属离子络合物 (DMP-—M+)稳定;二价金属离子(M2+)可能比一价金属离子(M+)更易使多核苷酸折叠。     

cis-Diamminodichloronickel and Its Interaction with Guanine and Guanine–Cytosine Base Pair

Comprehensive ab initio calculations are performed on cis-diamminodichloronickel (cisni) at the HF, DFT, and MP2 levels of theory. The results are compared to those obtained for cisplatin. The characteristics of the interactions of cisni with guanine (G) and guanine–cytosine (GC) base pair are also evaluated and compared to the interactions of cisplatin. Cisni causes similar geometric changes of the base as cis-platinum when complexed to guanine. The nickel, palladium and platinum complexes also show similar characteristics when complexed to GC base pair. However, this study predicts higher dissociation energy of the cisni chlorine ligands that indicate areas of differences between the title Ni and Pt and Pd complexes. Comparison of the G-cisni interaction energy to that of cisplatin and cispd indicate differences between the Ni and Pd complexes, but also reveals its closer similarities to cisplatin.     

Theoretical Study of the Metal–Metal Interaction in Dipalladium(I) Complexes

Correlated ab initio calculations have been performed on three dipalladium(I) complexes. These compounds differ both by the metal–metal interaction and by the metal–ligand interaction. The [Pd₂Cl₂(μ −H₂PCH₂PH₂)₂] complex exhibits a σ overlap between the two binding metallic orbitals and has no bridging ligand. In [Pd₂Cl₄(μ −CO)₂]²⁻, the leading interaction between the two palladium involves a π overlap between the metallic orbitals and goes through the two bridging CO ligands. In [Pd₂Cl₂(μ −CO)(μ −H₂PCH₂ PH₂)₂], a single CO ligand bridges the two palladium atoms which interact through a hybrid σ–δ overlap. The three compounds also differ by the metal–metal distances. Surprisingly enough, while the palladium atoms are formally d ⁹ in all these complexes, none of them is paramagnetic. We propose here a detailed analysis of the electronic structures of these compounds and rationalize their chemical structures as well as the role of back-donation in the CO bridged compounds. Finally, since highly correlated treatments are used to describe these complexes, a detailed study of the role of both non-dynamical and dynamical correlations is performed. Concerning the [Pd₂Cl₄(μ −CO)₂]²⁻ complex, this analysis has revealed that the complex is not bound at the lowest correlated levels of calculation and therefore dynamical correlation is alone responsible for its binding energy.     

Rationalizing the Structural Variability of the Exocyclic Amino Groups in Nucleobases and Their Metal Complexes: Cytosine and Adenine

The exocyclic amino groups of cytosine and adenine nucleobases are normally almost flat, with the N atoms essentially sp² hybridized and the lone pair largely delocalized into the heterocyclic rings. However, a change to marked pyramidality of the amino group (N then sp³ hybridized, lone pair essentially localized at N) occurs during i) involvement of an amino proton in strong hydrogen bonding donor conditions or ii) with monofunctional metal coordination following removal of one of the two protons.     

Theoretical Studies on the Interactions of Cations with Diazine

1 INTRODUCTION Interaction between cations and π electron systems is a kind of common and important non-covalent inter- action[1～21]. It could be observed in many systems, such as gas ion-molecule complexes and biological macromolecular proteins. Especially, in biological macromolecular systems, this interaction is signi- ficant for revealing the structures and functions of proteins or disclosing the atomic essence of protein- ligand effect. Interaction between benzene and metal ions h…     

胞嘧啶…NO复合物结构与性质的理论研究

用密度泛函理论在BL3YP/6-311＋G*基组水平上对胞嘧啶…NO复合物体系进行了理论计算, 发现了6个能量极小的复合物. 其结合方式是NO的N或O原子与胞嘧啶的N—H键形成氢键, 最稳定的复合物的结合能为－9.65 kJ/mol. NO的N原子与胞嘧啶的结合具有更强的优势, N结合的复合物中NO的键长缩短, 而O结合的复合物中NO键长伸长. 同时, 对复合物的振动分析发现, 在胞嘧啶中所有的与NO结合的N—H键的伸缩频率下降, 而所有氨基的面内弯曲振动频率是增加的.     

基于重金属配合物的阳离子磷光化学传感器

金属阳离子在生命科学和环境科学中扮演着重要的角色.在生命科学和环境检测领域,对这些金属阳离子进行定性和定量检测有着重要的意义.磷光重金属配合物以其优异的光物理性质在金属阳离子检测领域具有非常好的应用前景,如大的斯托克斯位移可以很容易区分激发和发射,长的发光寿命可使用时间分辨技术与背景荧光信号相区分以提高检测的信噪比和灵...     

2DFT Research of the Interaction between Metal Ions and CO2 along with H2O

The interaction between several different metal ions and H2O along with CO2 has been researched theoretically in the CO2 photocatalytic reduction with H2O system at the B3LYP level by DFT.The computational results revealed that relatively high valence metal ions loaded on TiO2 activated the H2O and CO2 consumingly,and it might be looked as some proofs for modified photocatalyst selecting.In addition,the metal ions conducted photoelectrons to prevent the re-combination of photoelectrons and holes during the reaction process.     

木犀草素与胞嘧啶相互作用的理论研究

采用密度泛函理论中的B3LYP方法,在6-31＋G＊基组水平上对木犀草素、胞嘧啶、木犀草素-胞嘧啶复合物进行结构优化和振动频率分析,得到了12种稳定复合物.并应用分子中的原子理论（AIM）分析、自然键轨道（NBO）理论分析得到复合物氢键性质和特征.通过基组重叠误差（BSSE）校正后的相互作用能、成键临界点电荷密度、二阶...     

Theoretical Investigation on Interaction between Guanine and Luteolin

The interacting patterns of the luteolin and guanine have been investigated by using the density functional theory B3LYP method with 6-31＋G＊ basis set. Eighteen stable structures for the luteolin-guanine complexes have been found respectively. The results indicate that the complexes are mainly stabilized by the hydrogen bonding interactions. Meanwhile, both the number and strength of hydrogen bond play important roles in determining the stability of the complexes which can form two or more hydrogen bonds. Theories of atoms in molecules and natural bond orbital have also been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes which were corrected by basis set superposition error are 6.04-56.94 kJ/mol. The calculation results indicate that there are strong hydrogen bonding interactions in the luteolin-guanine complexes. We compared the interaction between luteolin and four bases of DNA, and found luteolin-thymine was the strongest and luteolin-adenine was the weakest. The interaction between luteolin and DNA bases are all stronger than luteolin-water.     

金属螯合亲和色谱中固定金属与蛋白质的作用

在不同PHNaCl的磷酸缓冲体系,比较了牛血清蛋白（BSA）、核糖核酸酶（RNase)、细色素C（Cyt-C)和溶菌酶（Lys)在IDA裸柱和一些金属螯合柱上的保留特性,考察了固定金属对蛋白质保留行为的影响,指出蛋白质在强结合IDA－Cu柱上的保留主要受固定金属和蛋白质间配位作用支配,在弱亲和的IDA－Ni,IDA-Co和IDA－Zn柱上的保留主要受静电作用控制,配位作用为辅,讨论了金属螯合亲和色谱中影响蛋白质和金属配位的主要因素,金属离子的电荷和半径,配位原子对中心离子外层d轨道的影响,以及蛋白质表面配位的组氨酸数目,离解常数和取向,影响金属螯合配体和蛋白质静电作用的主要因素为溶液的PH和蛋白质的等电点pI.     

氟喹诺酮类药物与牛血清白蛋白作用的研究

用荧光猝灭法研究了ＢＳＡ与ＮＦＬＸ及ＯＦＬＸ之间的相互作用，根据Ｆｏｒｓｔｅｒ的能量转移理论，确定了能量给体－受体间的距离，根据荧光猝灭谐绘制了猝灭曲线，确定其猝灭过程是静态猝灭，用Ｌｉｎｅｗｅａｖｅｒ－Ｂｕｒｋ双倒数曲线测定ＮＦＬＸ－ＢＳＡ和ＯＦＬＸ－ＢＳＡ络合物的离解常数，并详细研究了１０种阳离子，４种阴离子与药物对ＢＳＡ竞争结合的影响，推测了药物与蛋白的主要作用力。     

Ni2＋与双甘氨肽相互作用的理论研究

使用密度泛函的B3PW91方法研究了Ni^2＋离子与二肽的相互作用, 优化了各种可能复合物的三重态、五重态和单重态. 研究结果表明所得配合物的基态为三重态, 基态复合物基本上是以二肽分子中碳链上的两个O原子和末端N原子形成的二齿或三齿配合物. 在气相中基态的最稳定复合物构型为三配位的³I, 而在溶液中为两性离子配合物³VIII. 在配合过程中, 静电相互作用占主导地位. 三重态的配位过程中配体的电子主要转移到空3d轨道和4s4p上而五重态中配体的电子主要转移到单占据d轨道上, 导致自旋密度转移到配体上去. 溶剂化过程中, 溶剂与溶质间的静电相互作用起主导作用.     

Theoretical Studies on the Intermonomer Interaction of F~-·(H_2O)_n (n = 1, 2)

1 INTRODUCTION Hydrogen bond plays an important role in the fields of physics, biology and chemistry. It has cap- tured the interest of chemists for a long time and reports about its theory and experiment have been well represented[1～6]. Concerning its theoretical inves- tigations, most of the emphases are placed on the weak interaction energy of intramolecular hydrogen bond. But studies on its spectrum behavior are rela- tively rare. These years spectrum behavior led by hydrogen bond h…     

Studies on Phosphate Effect of Cytosine and Its Novel Photoproduct

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[Ti(CO)6(MPEt3)]-(M=Au,Ag,Cu)配合物稳定性及其电子性质的量子化学研究

采用abinitioHF和密度泛函B₃LYP方法对[Ti(CO)₆(AuPEt₃)]^-配合物稳定性进行系统理论计算,并对Ti-Au金属-金属相互作用能运用完全均衡校正法对基函数重叠误差(BSSE)进行较正.理论优化的结构与X射线衍射晶体结构实验值基本相符,Ti-Au相互作用能为10.8575eV(B₃LYP/BSSE).进一步探讨Cu族元素为中心的同系配合物离子[Ti(CO)₆(MPR₃)]^-(M=Cu,Ag;R=Me,H)的电子性质及结合能规律,结果表明:Cu族化合物中,Au形成了较为稳定的化合物,表现出金属-金属相互作用影响比较明显.     

对二甲氨基苯甲酰腙衍生物与金属离子间的相互作用

合成了对二甲氨基苯甲酰缩噻吩(1)、呋喃(2)、苯(3)等腙类衍生物,并通过氢谱、碳谱和质谱进行表征,采用吸收光谱法研究了其与金属离子间的相互作用。结果表明,含噻吩基团的腙衍生物1与Hg2+结合,形成1∶1稳定的配合物,结合常数为9.7×104L·mol-1,噻吩衍生物1对Hg2+响应的线性范围为1.0~18μmol/L,检出限为0.28μmol/L,且Cu2+,Fe3+和Ni2+等共存金属离子不干扰测定。对照化合物中的呋喃衍生物2可1∶1结合Hg2+,Zn2+和Cd2+,其与Hg2+和Zn2+的结合常数分别为6.5×104L·mol-1和5.0×105L·mol-1;而苯衍生物3对测试的金属离子均未显示光谱变化。由此可见,化合物1对Hg2+的高选择性结合作用源于结合基团中不同配位原子的组合,其所含的S和O均参与了与Hg2+的配位作用。     

CH2FCF3与O(1D)反应机理的理论研究

用量子化学密度泛函理论(DFT)和G3(MP2)B3方法,对O(1↑D)与CH2FCF3的反应进行了研究．在UB3LYP/6-31G(d)计算水平上,优化了反应势能面上各驻点的几何结构,在G3(MP2)B3水平上进行了单点计算,并利用UB3LYP/6-311 G(3df,3pd)计算的波函数进行了电荷密度分析．通过内禀坐标(IRC)计算和振动分析,对反应过渡态进行了确认,并确定了反应机理．