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1.
合成并表征了一个新的Ru(II)配合物[Ru(bpy) 2(hedppc)](ClO 4) 2 {bpy=2,2'-联吡啶, hedppc=二联吡啶[3,2- a: 2',3'- c]吩嗪-11-羧酸(2-羟乙基)酯}. 通过紫外-可见吸收光谱、与溴化乙锭竞争实验、粘度测量和DNA裂解实验研究了配合物与小牛胸腺DNA的相互作用性质. 结果表明配合物以插入模式与DNA键合,键合常数 Kb=(6.99±1.34)×10 6 mol -1•L ( s=2.03±0.04)与母体配合物[Ru(bpy) 2 (dppz)] 2+相近,但光致发光和溶剂变色等光学性质与[Ru(bpy) 2 (dppz)] 2+有明显的差别. 相似文献
2.
比较了BP86、PBE、B3LYP、B3PW91、BHandHLYP、PBE0、X3LYP、CAM-B3LYP、TPSS、M06L、M06和M06-2X等12种采用了广义梯度近似(GGA、hybrid GGA、meta-GGA和hybrid meta-GGA)的密度泛函理论(DFT)方法在三个三价铀复合物表征中的应用. 研究模型采用铀复合物催化CO 2和CS 2官能团化反应中的三个中间体(Tp *) 2U- η 1-CH 2Ph (Cpd2), (Tp *) 2U- κ 2-O 2CCH 2Ph (Cpd3) 和(Tp *) 2U- κ 2-S 2CCH 2Ph (Cpd4). 研究发现, B3LYP 和B3PW91 在几何结构和电子结构方面优于其它方法. 基于分子轨道理论的MP2 方法在Cpd2 和Cpd3 的表征中给出与DFT方法相近的结果, 而在Cpd4 的表征中表现出较大的差异. 这可能是由于同样是单参考态方法的MP2捕捉到了与DFT方法不同的电子结构. 同时, 通过对比分别采用小核赝势(5f-in-valence)和大核赝势(5f-in-core)基组处理铀原子的计算结果, 发现对测试的模型体系, 两种处理方法可获得相近的热力学能量. 与以往主要关注高价态锕系复合物的处理方法的评估工作不同, 本项工作适应逐渐增加的对低价态锕系分子体系的研究的需求, 对12 种常用的密度泛函理论方法在低价态锕系复合物研究中的应用进行了评估, 期望为处理类似体系的研究工作提供参考. 相似文献
3.
用密度泛函 B3LYP 方法得到一系列不同管径的氨基-硝基双取代纳米管NH 2-( n,0)CNT-NO 2 ( n=5~10)的几何结构. 用CAM-B3LYP 方法计算了体系的第一超极化率( β0). 研究表明, β0 对管径大小有着极强的依赖性. 特别是对偶数纳米管( n=6, 8 和10), 其 β0 (5.5×10 3~9.8×10 4 au)是奇数纳米管 β0 (1.0×10 3~2.8×10 3 au)的5~35 倍. 相似文献
4.
在溶剂热条件下,以不对称三羧酸5-(6-羧酸-2-萘基)-间苯二羧酸(H3L)为配体合成了2个镉的金属-有机骨架化合物:{[Cd 3L 2(H 2O) 3]·6DMF} n(1)和{[Cd 3L 2(H 2O) 4]·3DMA} n(2)。通过X射线单晶衍射,粉末衍射,热重和红外光谱进行了结构表征。结构分析表明,1和2形成3,6-连接的三维结构,其拓扑符号分别为:(4 5.6 4.8 6)(4 3) 2和(6 12.8 3)(6 3) 2。此外,还对2个化合物进行了荧光分析。 相似文献
5.
使用密度泛函理论(BP86)结合非平衡态格林函数(NEGF)方法研究金属串配合物[Cu 2Pt(npa) 4X 2] (X=Cl -(1), NCS -(2); npa=2-naphthyridylphenylamine)的电子结构和电子传输性质, 研究发现: (1)由于轴向配体NCS -与Cu的结合比Cl -的强, 使配合物1的Cu-Cu键比2的强而Cu-Pt键比2的弱, 故1的π *Pt dxz/yz轨道与π *Cu-Cu能级差Δ E比2小. (2) 1和2的传输通道均是β自旋的π *轨道, 主要由π *Cu-Cu 和π *Pt dxz/yz轨道组合而成. Δ E越小π *越离域, 传输能力越强. 在负偏压下和正偏压小于0.15 V时, 1的电流大于2; 但正偏压大于0.15 V后2的β电流显著高于1. (3) 2具有较好的整流效应. Δ E越大, Pt→Cu方向的传输越容易, 整流效应越强. 正偏压下2的电流显著大于负偏压下的电流, 0.15 V后2的整流比比1高10~40倍. (4)因Δ Eβ< Δ Eα, α自旋通道传输能力小于β自旋的, 1和2具有良好的自旋过滤效应(高达80%~99%). 相似文献
6.
应用密度泛函理论BP86方法结合自然键轨道分析方法对具有分子导线潜在应用前景的金属串配合物[Ni 3(L) 4(NCS) 2](L = dpa - (1), mpta - (2), mdpa - (3), mppa - (4))进行研究,分析了桥联配体L对Ni―Ni相互作用和磁耦合性质的影响.结果得到: (1)配合物的基态均是对应于五重态(HS)的反铁磁(AF)单重态, HS的能量和结构与AF态相近, Ni 36+链形成了三中心四电子σ键(σ 2σ nb1σ *1). (2) dpa -引入甲基成为mdpa -,对Ni―Ni、Ni―N距离影响不大; 3H-吡咯环和噻唑环取代吡啶环后, N1―N2、Ni―Ni距离增大, Ni2―N2键长缩短,但噻唑环的影响较小;故Ni―Ni相互作用强度为1 ≈ 3 > 2 > 4. (3)预测了3和4的 Jab值为-103和-88 cm -1,随Ni―Ni相互作用增强磁耦合效应增大. Ni―Ni相互作用越大,通过Ni 36+链σ型轨道的直接磁耦合越强; Ni2―N2键越强,通过涉及桥联配体的间接磁耦合越强,直接磁耦合比间接磁耦合更强. 相似文献
7.
采用DFT/TDDFT方法研究了二米基硼B(Mes) 2基团修饰的一类Ir(ppy) 2(acac)配合物1~3的光物理性质. 计算了电子结构,吸收和发射光谱以及自旋轨道耦合矩阵< T 1α|H SOC|S n >和辐射跃迁速率( kr),探讨了取代基位置不同对磷光辐射和非辐射跃迁性质的影响. 研究结果表明:向ppy配体的吡啶环引入B(Mes) 2基团,能够加强金属铱(Ir)与配体乙酰丙酮(acac)的相互作用,减小单-三重态能级差Δ E(S 1-T 1),提高系间窜跃速率和磷光辐射跃迁速率. 向ppy配体的苯环引入B(Mes) 2基团则增大了S 0与T 1的结构变形和自旋轨道耦合矩阵< S 0|H SOC|T 1 >,使非辐射跃迁速率增加. B(Mes) 2基团位置异构,导致金属d轨道分裂方式不同,其在三个方向的自旋轨道耦合作用不同,辐射跃迁和非辐射跃迁都随之改变. 从理论上解释了通过对ppy配体的吡啶环修饰可获得高磷光量子产率的原因. 相似文献
8.
采用密度泛函理论方法研究了具有仿生固氮结构的两类化合物[Cp*Fe(μ-η 2:η 2-bdt)(μ-η 1:η 1-MeN=NMe)FeCp*]以及[Cp*Fe(μ-SEt) 2(μ-η 1:η 1-MeN=NMe)FeCp*]的90种不同结构, 调变过渡金属中心, 研究不同自旋态下(单重态和三重态)具有side-on或end-on配位键型的双核双氮过渡金属配合物, 基于计算结果分析了BDT(邻苯二硫酚)和乙基类型配体的不同过渡金属配合物活化双氮的程度. 研究结果表明, N-N键活化程度与配合物过渡金属中心所在周期存在密切关系, 更高周期对双氮的活化程度更高, 同周期金属过渡金属配合物对N-N键的活化程度从第四副族至第八族呈现折线型下降, 同时, 过渡金属中心的外层价电子数的奇偶性对双氮的活化程度具有一定影响. 此外, side-on键型对双氮的活化程度要高于end-on键型, 具有不同基团的同种骨架配体对N-N键的活化能力没有明显区别. 相似文献
9.
以苯并15冠5和钼多酸为原料, 用水热法合成了两个新颖的超分子配合物[Na(B30C10)][Mo 6O 19] (1)和[NaL(CH 3CN)][NaL][ α-PMo 12O 40][NaL 2] (L=B15C5) (2), 并用单晶X射线衍射测定了它们的晶体结构. 配合物1属单斜晶系, 空间群为 C2/ m, 它包含三个基本单元: Na +, B15C5和Mo 6O , 冠醚分子和Na +配位, 并通过静电作用力和多酸分子相连. 配合物2属三斜晶系, 空间群为 P-1, 它包含一个[ α-PMo 12O 40] 3-离子和三个钠离子配合物. [Na(B15C5)] +通过Mo-O-Na-O键和多酸阴离子相连. 相似文献
10.
利用密度泛函理论在B3LYP/6-311G*水平上对碱土金属叠氮化合物(CaN 6) n ( n=1~5)团簇各种可能构型进行了几何优化, 预测了各团簇的最稳定结构. 并对最稳定结构的成键特性、电荷分布、振动特性及稳定性进行理论研究. 结果表明, 叠氮化合物中叠氮基以直线型存在, CaN 6团簇的最稳定结构为线型结构, (CaN 6) n ( n=2~5)团簇首先由两个叠氮基与两个Ca原子构成一个近似菱形, 再由菱形相互垂直形成链状最稳定结构; 叠氮基中间的N原子显示正电性, 两端的N原子显示负电性, 且与Ca直接作用的N原子负电性更强, 金属Ca原子和N原子之间形成很强的离子键; (CaN 6) n ( n=1~5)团簇最稳定结构的IR光谱分为4个部分, 其最强振动峰均位于2195~2280 cm -1, 振动模式为叠氮基中N-N键的反对称伸缩振动; 稳定性分析显示, (CaN 6) 3和(CaN 6) 5团簇相对于其他团簇较为稳定. 相似文献
11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。 相似文献
13.
The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness. 相似文献
14.
Two vanilloids, (5 E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one ( 1) and 4-[3-hydroxydecyl]-2-methoxyphenol ( 2), isolated from the dried seeds of Grains of Paradise ( Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared. 相似文献
15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992. 相似文献
16.
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。 相似文献
17.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite ( P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time ( th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with ( th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with ( th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700 oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides
and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques.
Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated.
Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997. 相似文献
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。 相似文献
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