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1.
采用密度泛函的方法,结合导体极化连续模型研究了水溶性二价钌-甲基咪唑类配合物[Ru(MeIm)4iip]2+ (1)、[Ru(MeIm)4tip]2+(2)和[Ru(MeIm)42ntz]2+ (3)的电子结构、DNA的键合倾向及构效关系.在水溶液中几何优化的基础上分析了配合物的电子结构特征,并合理解释了配合物与DNA的键合倾向.计算结果表明,在主配体上用噻吩代替咪唑取代基可以有效提高配合物与DNA的键合力;同时,在主配体的骨架上引入强电负性的N原子及NO2基团可以明显降低配合物最低未占据分子轨道能量及前沿分子轨道能量差.基于以上计算结果,预测所设计的配合物3具有最大的DNA键合力常数.另外,详细分析了配合物1、2的构效关系及抗肿瘤作用机理,并预测了配合物3的抗肿瘤活性.最后,用含时密度泛函方法对配合物的电子吸收光谱进行了计算和模拟,并与实验结果进行了对比分析.  相似文献   

2.
本文研究了中性Ni2CO5配合物的势能图,发现一个C2v双桥羰基新构型,与以前报道的三羰基桥联的D3h构型竞争Ni2CO5的基态结构. 尽管三桥式异构体拥有更有利的(18,18)电子构型,即双金属中心都满足18电子规则,中性的Ni2CO5$配合物更倾向于(18,16)电子结构的双桥式几何. 异构化能量分解分析表明,这样的结构优选是静电作用和轨道相互作用极大化的结果.  相似文献   

3.
利用光外差速度调制分子光谱技术测得氮分子离子A2Πu-X2Σ+g 带系的(3,1)、(4,2)、(5,3)、(8,5)带的谱线,其中(5,3)带是第一次被指认.利用测得的4个带以及文献中的14个带的谱线进行全局拟合,得到了一系列的分子常数(υA=0~9和υA=0~5).  相似文献   

4.
本文利用时间切片离子成像技术对OCS分子进行了真空紫外波段的光解动力学研究. 在四个光解光波长(从129.32到126.08 nm)下测量了硫原子解离产物S(3PJ=2,1,0)、S(1D2)、S(1S0)的速度影像,并从中清晰地发现了四个主要的解离产物通道:S(3PJ=2,1,0)+CO(X1Σ+),S(3PJ=2,1,0)+CO(A3π),S(1D2)+CO(X1Σ+)和S(1S0)+CO(X1Σ+). 在实验影像中,产物CO分子的部分振动态结构能够得到分辨. 实验还获取解离产物总平动能谱,产物分支比和角分布. 对实验结果进行分析显示除绝热解离通道S(3PJ=2,1,0)+CO(A3π)之外,在其他三个产物通道中非绝热效应都起到非常重要的作用.  相似文献   

5.
本文采用共聚法制备了一种新型苯基功能化纤维状Fe3O4@SiO2@KCC-1(Fe3O4@SiO2@KCC-1-phenyl)材料,用于环境水样中邻苯二甲酸酯的磁性萃取. 制备的Fe3O4@SiO2@KCC-1-phenyl展现了单分散的球形纤维状、较强的磁性(29 emu/g)和一个丰富的π电子体系. 研究和优化了洗脱溶剂的种类、吸附剂的用量、萃取时间和可重复使用性等因素对分析物萃取效率的影响. 在最佳条件下,用高效液相色谱方法,采用Fe3O4@SiO2@KCC-1-phenyl萃取分离及测定环境水样中的邻苯二甲酸酯类化合物. 结果表明,本方法具有良好的线性(0.1∽20 ng/mL)、低的检测限(7.5∽29 μg/L, S/N=3). 将该方法应用于不同环境水样中邻苯二甲酸酯类化合物的测定,回收率为93%∽103.4%,相对标准偏差为0.8%∽8.3%.  相似文献   

6.
本文采用含时波包方法和七维约化量子模型研究了典型碳氢氧化反应O(3P)+CHD3→OH+CD3中反应分子CHD3的转动模式特异性. 发现理论计算反应几率依赖于CHD3转动量子数J在分子对称轴上的投影$K$和在O-CHD3分子间轴上的投影Ktot,即PKtot=K=0>PKtot=K=J>PKtot=J,K=0=PKtot=0,K=J. 这种关系可以用反应物分子相对取向进行解释. 另外,反应物CHD3的转动激发(J≤4)表现出比较弱的促进作用,但是K=0转动态激发的促进作用比K=J的强,主要得益于K=Ktot=0分量的贡献. 该分量对应于CHD3的滚动转动,这种运动形式可以增大初始有效反应碰撞角度的范围.  相似文献   

7.
本文利用时间切片离子速度成像技术在134∽140 nm波段研究了OCS分子经由F 31Π里德堡态的真空紫外光解离动力学. 在选取的5个分别对应OCS(F 31Π, v1=0∽4)的伸缩振动激发的光解波长,实验测得了来自CO(X1Σ+)+S(1D2)产物通道的SS(1D2))实验影像,并获得了总平动能谱和CO(X1Σ+, v)共生产物的振动布居及角分布. 结果分析表明OCS分子解离生成CO(X1Σ+)+S(1D2)产物的过程经历了上态F 31Π 与C?v和Cs构型的下电子态间非绝热耦合过程. 实验结果显示了很强的波长相关性:OCS (F 31Π, v1)的较低转动激发态(v1=0∽2)和较高转动激发态(v1=3, 4)的CO(X1Σ+)产物的振动布居和角分布具有显著差异,表明该解离过程中具有不同的解离机理. 本结果提供了振动耦合可能对真空紫外光解离动力学产生关键作用的相关证据.  相似文献   

8.
本文合成了磁性金属有机骨架材料Fe3O4@[Cu3(btc)2],并作为分散微固相萃取的吸附剂用于四环素类抗生素的富集. 对萃取的条件,包括萃取时间、溶液pH和洗脱溶剂对四环素类抗生素萃取效率的影响进行了研究. 结果显示Fe3O4@[Cu3(btc)2]可以有效富集四环素类抗生素,而四环素类抗生素与Fe3O4@[Cu3(btc)2]之间的静电相互作用主导了这一过程. 利用分散微固相萃取结合液相色谱-串联质谱法对天然水中的四种四环素类抗生素(土霉素,四环素,金霉素和多西环素)残留进行了测定. 四种抗生素的检出限(S/N=3)为0.01∽0.02 μg/L,定量限(S/N=10)为0.04∽0.07 μg/L. 河水和养殖水中四环素三个水平的加标回收率为70.3%∽96.5%,相对标准偏差为3.8%∽12.8%. 结果表明,基于磁性金属有机骨架材料的分散微固相萃取可以从水中简单、快速、高效地富集四环素类抗生素.  相似文献   

9.
利用脉冲激光溅射-超声分子束载带方法制备了气相Ti+(CO2)2Ar和Ti+(CO2)n(n=3-7)络合物离子.采用红外光解离光谱研究了这些选定的质量离子的振动光谱. 对于每一种络合物离子, 在CO伸缩振动频率范围都观察到了振动峰,表明这些离子具有插入的OTi+CO(CO2)n-1结构. 对于n≦5的OTi+CO(CO2)n-1离子,其CO振动和CO2的反对称伸缩振动频率都比自由的CO和CO2的频率要高,表明CO和CO2配体与中心金属离子之间主要是静电相互作用.实验结果还表明TiO+可以直接络合五个配体(1个CO和4个CO2分子).对于n=2络合物体系,除了插入的OTi+CO(CO2)结构以外,还观察到了具有弯曲结构的OCO-Ti+-OCO异构体的存在  相似文献   

10.
本文使用交叉分子束方法研究了氟原子和振动激发态氘分子D2(v=1, j=0)的反应. 使用受激拉曼抽运的方法制备了振动激发的D2分子. 实验中未观测到来自于旋轨耦合激发态氟原子F*(2P1/2)与振动激发态D2分子的贡献. 观测到来自于旋轨耦合基态氟原子F(2P3/2)和振动激发态D2的反应信号,相应的产物DF分子布居于v''=2,3,4,5振动态上. 与振动基态反应F+D2(v=1,j=0)相比,振动激发态反应F+D2(v=1,j=0)生成的DF产物转动分布更“热”. 获得了振动激发反应的四个碰撞能在0.32至2.62 kcal/mol范围内的微分反应截面. 在最低的碰撞能0.32 kcal/mol下,所有振动态的DF产物都以后向散射为主. 随着碰撞能的增加,DF产物的角分布逐渐从后向转移到侧向. 测量了DF(v''=5)产物的前向微分散射截面随碰撞能变化的曲线. 前向散射的DF(v''=5)信号出现于1.0 kcal/mol. 在2.62 kcal/mol碰撞能下DF(v''=5)主要为前向散射.  相似文献   

11.
In an effort to better understand the biological efficacy of the tridentate aroyl hydrazone Cu(II) complexes, the Cu(II) complex of di-2-pyridyl ketone isonicotinoyl hydrazone ligand (HL), {[Cu(L)(H2O)]·H2O·NO3}n (C1) was synthesized and characterized. Single crystal X-ray study reveals that complex C1 forms 1D zigzag chains in solid state. In water, the hydrolysis of the 1D zigzag chains was observed, and finally formation of monomeric species. In vitro studies revealed that complex C1 showed significantly more anticancer activity than the ligand alone. Investigation of the anticancer mechanisms of C1, confirmed that the Cu(II) complex exhibit a strong capacity to promote productions of reactive oxygen species (ROS), leading to caspase-dependent apoptotic cell death.  相似文献   

12.
The spectroscopic constants of s-trans (E)-acrylaldehyde oxime of normal, CH2CHCHNOH, and deuterated, CH2CHCHNOD, species were refined by adding a-type R-branch transitions observed in the frequency range of 34-40 GHz in the ground vibrational state. For s-trans (Z) form, the spectroscopic constants of normal species were refined by refitting the reported frequencies with four b-type Q-branch transitions and those of deuterated species were determined by the least-squares fitting of the observed a-type R-branch transitions in the ground vibrational state. The spectroscopic constants of two isomers of normal species were also determined in the vibrationally excited states. The inertial defects (ΔI=IcIaIb) of normal and deuterated species were determined to be −0.042(24) and −0.064(17) u Å2 for s-trans (E)-1 form, and −0.0536(8) and −0.063(11) u Å2 for s-trans (Z)-1 form, respectively. From the rs coordinates of the hydroxyl hydrogen atom determined for s-trans (Z)-1 form, its OH bond was concluded to be at the trans position with respect to the CN double bond. The dipole moments of deuterated species of s-trans (E)-1 form and those of normal and deuterated species of s-trans (Z)-1 form were determined. The structural parameters of r(C2C3), ∠C1C2C3, ∠C2C3N, and ∠C3NO for s-trans (E)-1 and s-trans (Z)-1 forms were adjusted separately using to their rotational constants observed. It was found that the bond angle of ∠C2C3N in s-trans (Z)-1 form are much wider than that in s-trans (E)-1 form by about 10°. The difference between the observed and calculated (using MP2/6-311++G (d,p) level) rotational constants of s-trans (Z)-1 form was larger than that of s-trans (E)-1 form.  相似文献   

13.
The previously unknown molecule C-nitrosomethanol [H2C(OH)(NO)] and seven of its isotopic modification [13C, 18OH, 15N, D3, D3-15N, H2C(OD)(NO), and HDC(OH)(NO)] have been photolytically prepared from the corresponding methylnitrite isotopes in a low-temperature argon matrix. By irradiating methylnitrite into its S1(nπ1 ← S0 transition at 365 nm, the molecule is transformed into a hydrogen-bonded 1:1 complex between formaldehyde and nitroxyl. Photolysis of this complex produces either the trans (λexc = 345 nm) or the cis (λexc ≥ 645 nm) isomer of nitrosomethanol. Selective photoisomerization processes permit interconversion of the conformers (cis → trans with λexc = 510 nm and trans → cis with λexc ≥ 645 nm). The ir spectra (40–170 cm?1) of cis- and trans-nitrosomethanol were measured and analyzed in conjunction with a normal coordinate analysis based on a constrained valence force field (transferable valence force field approach). The frequencies of cis- and trans-nitrosomethanol were assigned and their force fields determined.  相似文献   

14.
本文利用飞秒瞬态吸收光谱结合量化计算研究了反式-4-甲氧基偶氮苯的超快激发态动力学和光异构过程. 瞬态光谱中在400∽480 nm波段出现永久的正吸收,表明反式分子被激发到第二激发态后最终产生了顺式结构. 在乙醇和乙二醇溶剂环境中分别获得了三个衰减组分,时间分别为0.11、1.4、2.9 ps和0.16、1.5、7.5 ps. 快速的时间组分是源自第二激发态弛豫到第一激发态的内转换过程. 另外两个组分和第一激发态的弛豫相关:一个是经第一激发态的内转化和光异构过程,另一个是顺式结构的振动冷却过程. 基于不同溶剂环境中的动力学差别,证实了光异构路径是反转机制而不是旋转机制.  相似文献   

15.
Magnetic properties, Mössbauer spectra and crystal structures of spin-crossover iron(III) complexes with a quinquedentate ligand [FeLX]BPh4 are reported. X and L denote a unidentate ligand and a quinquedentate ligand, respectively. [Fe(mbpN)(im)]BPh4 shows spin-crossover behavior in an appropriate organic solvent, and [Fe(mbpN)(lut)]BPh4, [Fe(bpN)(py)]BPh4 and [Fe(salten)X]BPh4 (X=4me-py or 2me-im) show spin-crossover behavior in a solid and in an organic solvent. It was found that the ligand field strength of salten was stronger than that of mbpN. The rates of spin-state interexchange in the complexes are as fast as the inverse of the lifetime (1×10–7 s) of the Mössbauer nuclear level. The Mössbauer spectroscopic behavior of [Fe(mbpN)(lut)]BPh4 and [Fe(bpN)(py)]BPh4 is different to that of [Fe(salten)X]BPh4 (X=4me-py or 2me-im). The difference was ascribed to the different geometrical positions of the corresponding anions.  相似文献   

16.
本文报道了氯化氢-水二聚体的两种同位素,HCl-H2O和DCl-H2O(DH)的J=1分子内和分子间振转态的全维和完全耦合量子束缚态计算. 本研究补充了我们最近对于这两类体系J=0九维(9D)振动水平结构的理论研究,并采用相同的精确9D置换不变多项式-神经网络势能面. 该计算得到了所有这些分子间和分子内低能的振转态的基本量,将结果与相同二聚体的9D J=0计算的结果进行了比较. K=1和K=0本征态之间的能量差异表现出与分子间振转态的明显变化,为此本文提供了定性的解释.  相似文献   

17.
Electronic structures of binuclear ruthenium complexes [Ru2(terpy)2(tppz)]4+ ( 1A ) and [Ru2Cl2(L)2(tppz)]2+ {L = bpy ( 2A ), phen ( 3A ), and dpphen ( 4A )} were studied by density functional theory calculations. Abbreviations of the ligands (Ls) are bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline, dpphen = 4,7‐diphenyl‐1,10‐phenanthroline, terpy = 2,2′:6′,2″‐terpyridine, and tppz = tetrakis(2‐pyridyl)pyrazine. Their mononuclear reference complexes [Ru(terpy)2]2+ ( 1B ) and [RuClL(terpy)]+ {L = bpy ( 2B ), phen ( 3B ), and dpphen ( 4B )} were also examined. Geometries of these mononuclear and binuclear Ru(II) complexes were fully optimized. Their geometric parameters are in good agreement with the experimental data. The binuclear complexes were characterized by electrospray ionization mass spectrometry, UV–Vis spectroscopy, and cyclic voltammograms. Hexafluorophosphate salts of binuclear ruthenium complexes of 3A and 4A were newly prepared. The crystal structure of binuclear complex 1A (PF6)4 was also determined. Orbital interactions were analyzed to characterize the metal‐to‐ligand charge‐transfer (MLCT) states in these complexes. The Cl? ligand works to raise the orbital energy of the metal lone pair, which leads to the low MLCT state. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

18.
采用电化学原位红外光谱技术研究了多晶Pt电极上甲酸的分解反应. 研究发现,在恒电位下(0.4 V vs. RHE)从不含甲酸的支持电解质溶液切换到含甲酸的溶液时,COad的生成速率在切换的最初也就是甲酸根的覆盖度为零最大,切换后的1 s内甲酸根的覆盖度达到平衡,而COad的生成速率逐步降低. E由0.75 V变至0.35 V的电位阶跃实验显示:电位阶跃后的瞬间,甲酸根的红外光谱强度迅速降低,而COad的生成强度随时间缓慢增加. 实验表明甲酸根不是甲酸脱水生成CO的反应活性中间体.  相似文献   

19.
用光电子成像技术和从头算法研究Ag-(CH3OH)x (x=1, 2)和AgOCH3-. 从AgOCH3-振动分辨的光电子谱得 到AgOCH3-的绝热和垂直电离能分别为1.29(2)和1.34(2) eV. Ag-(CH3OH)1,2相似文献   

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