骨显像放射性药物锝-双膦酸盐配合物99mTc-MDP的结构

运用密度泛函理论方法对锝标记双膦酸盐配合物^99mTc-MDP进行了结构预测和计算, 其中MDP代表亚甲基双膦酸. 根据几何异构、构象异构、电荷异构和自旋态异构等特性预测该化合物共有14种异构体. 基于B3LYP/LANL2DZ水平优化的分子结构和计算的总能量,确定了两种稳定异构体,并与实验结构进行了比较. 运用B3LYP/6-31G*(LANL2DZ用于Tc, cc-pVDZ-pp用于Tc)和B3LYP/DGDZVP方法对化合物的稳定结构进行了计算. 理论计算值与实验值吻合较好,而基     

羰基化合物分子距边矢量与其13C NMR δC的关系

通过对155个羰基化合物中羰基碳原子的¹³C NMR谱与其分子距离-边数矢量(MDE)、立体效应参数(γ 效应)关系的研究，发现羰基化合物羰基碳的¹³C NMR谱化学位移可表示为：
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δ_C=a+bμ₅₁+cμ₅₂+dμ₅₃+eμ₅₄+fγ
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此式不仅在一定程度上表明了羰基化合物¹³C NMR谱化学位移与其分子结构信息之间的关系，同时也提供了一种计算羰基化合物¹³C NMR化学位移的新方法，并对解析和预测其¹³C NMR谱提供了理论依据.      

芳香族硝基化合物的核四极共振参数的HARTREE-FOCK计算

运用RHF近似方法,在不同高斯基组下用Gaussian98程序计算数种芳香族硝基化合物的核四极耦合常数和不对称参数. 其中,RHF/3-21G下的计算结果最合理,乘以校正系数后,核四极耦合常数计算值与实验值的相关性达到0.91.     

离子性指数、立体效应参数与膦类化合物31P NMR δP的关系

利用离子性指数(INI)和立体效应参数（α、β、γ）对100个膦化合物中磷原子进行结构表征，并与其核磁共振磷谱(³¹P NMR)建立了优良的定量构谱相关(QSSR)模型：δ_P=-163.695 3-1.003 1INI+34.632 7α+13.892 9β-3.331 7γ. 建模的计算值、留一法(Leave-One-Out, LOO)交互校验(Cross-Validation, CV)预测值的复相关系数(R)分别为0.976 5和0.973 9. 所建模型不仅在一定程度上阐明了膦类化合物³¹P NMR谱化学位移与其分子结构信息之间的关系，同时也提供了一种从理论上计算膦类化合物³¹P NMR谱化学位移的新方法，并对深入了解膦类化合物结构与性能的关系及解析、预测其³¹P NMR谱提供了一定的理论依据.     

卷丹皂苷A和甾体皂苷的NMR特征

应用2D NMR技术：¹H-¹H COSY、HMQC、HMBC全归属新化合物卷丹皂苷A和已知化合物麦冬皂苷D′ 的碳和氢质子信号，总结薯蓣皂苷元类型甾体皂苷的NMR特征，为该类型化合物的结构鉴定提供光谱学依据.     

第一原理研究铝锂金属间化合物

运用密度泛函理论系统地研究了二元铝锂金属间化合物Al₃Li、AlLi、Al₂Li₃和Al₄Li₉的结构、形成热、弹性和电子结构.通过计算四种金属间化合物的形成热,证明了金属间化合物中铝和锂之间具有强烈的化学作用. 在富锂金属间化合物中,随着锂的含量的增加,金属间化合物热力学稳定性呈线性减弱. 计算金属间化合物的单晶弹性常数可以得出四种金属间化合物都是机械稳定的. 运用Voigt-Reuss-Hil     

新型β-氨基醇及其中间体的合成与波谱研究

由D-木糖出发，经过杂D-A 反应、Henry反应、合成了中间体(1αS，2αR， 3αS，4S，7E，9αR，10αR)-1，2∶9，10-O-二异丙叉基-3-硝甲基-5，6-二脱氧-7-烯-4-氧化-1，4∶7，10-二呋喃-4，8-吡喃糖（化合物1），再经催化氢化，立体选择性地得到了含高碳糖结构片断的β-氨基醇(1αS，2αR， 3αS，4S，7αS，8βR，9αR，10αR)-1，2∶9，10-O-二异丙叉基-3-氨甲基-5，6-二脱氧-4-氧化-1，4∶7，10-二呋喃-4，8-吡喃糖（化合物2）， 通过DEPT和¹H-¹H COSY，HMQC，HMBC等2D NMR 技术对化合物1的¹H和¹³C NMR数据进行了全归属和较详细的解析并探讨了其ESI-MS/MS质谱裂解规律. 同时得到化合物1的还原产物化合物2的¹H，¹³C NMR归属.     

系列CoMnZnZ四元Heusler化合物的结构和半金属铁磁性

通过第一原理计算理论预测了CoMnZnZ (Z=Si, Ge, Sn, Pb)系列Heusler合金的弹性常数、电子结构和磁性,并根据弹性常数计算得到弹性模量等参量,计算了该系列化合物声速和德拜温度.计算采用全势线性缀加平面波方法,交换相关函数采用基于Perdew-Burke-Ernzerhof的广义梯度近似泛函.弹性模量结果表明晶体呈现韧性特征;承受剪切的性能弱于承受单轴压缩的性能;结构组成具有较低的各向异性性能.电子结构的计算显示CoMnZnZ (Z=Si, Ge, Sn)三个化合物属于半金属铁磁体,但是CoMnZnPb化合物并不显示半金属特性. CoMnZnZ (Z=Si, Ge, Sn)三个化合物的磁矩通过Slater-Pauling法则进行计算得到的量值与第一原理计算得到的完全一致,遵从总的价电子数减去28的Slater-Pauling法则,三个化合物磁矩为整数且自旋极化率为100%.利用轨道杂化理论解释了此系列化合物半金属性的根源.     

脂肪酮和脂肪酰卤羰基17O-NMR化学位移的研究

提出计算脂肪酮和脂肪酰卤羰基¹⁷O-NMR化学位移的公式：δ_cal=δ_0n+C×Δα，通过线性回归法确定了22种取代基参数.经回归检验表明该公式计算结果置信度为99.5%，与实验值的偏差Δδ在10.0以内的羰基¹⁷O-NMR化学位移计算值在90%左右.     

草苁蓉中2个单萜苷类化合物的NMR研究

从草苁蓉75%乙醇提取物中分离得到了2个单萜苷类化合物,结合其理化性质,并通过1D NMR（¹H NMR,¹³C NMR）及¹H-¹H COSY、HSQC、HMBC、NOESY等多种波谱学方法进行结构鉴定,鉴定2个化合物分别为β-D-glucopyranose 1-(3,7-dimethyl-2-trans-6-octadienoate)(化合物1)和6,7-dihydrofoliamenthoic acid diglucoside（化合物2）,其中化合物1为新化合物,化合物2为第1次从列当科植物中获得.     

Isotope Effects in the Electrochemical Reduction of Oxalic Acid-D2 and Benzoic Acid-D

Abstract

The electrochemical reduction of model carboxylic acid at lead cathodes in deuterated media was studied for potential use in the synthesis of special deuterated compounds.

Oxalic acid-d₂ in D₂O gives good yields of glyoxylic acid-d₂. An unexpected large isotope effect of 5.3 ± 1.7 was found in this reaction, leading to significant depletion of deuterium content in the aldehyde group.

Benzoic acid-d in CD₃OD/diluted D₂SO₄ yields benzyl alcohol-d, 7,7-d₂. The isotope effect of 2.4 ± 1.0 is within the expected range. No deuterium is incorporated into the aromatic nucleus. Essentially unlabelled benzyl alcohol is obtained in CD₃OH/dil. H₂SO₄.     

Insights into unusual stability of 5‐membered‐ring endocyclic benzyl carbocations in aqueous solution

The acyclic o‐oxygen benzyl carbocation 1 , the 6‐membered‐ring endocyclic o‐oxygen benzyl carbocation 2 , and the 5‐membered‐ring endocyclic o‐oxygen benzyl carbocation 3 were used as model compounds to get insights into the general phenomenon for the unusual stability of the 5‐membered‐ring endocyclic benzyl carbocations in aqueous solution. The hydride‐ion affinities of 1 , 2 , and 3 in gas phase, acetonitrile, and DMSO were calculated and compared by the density functional theory method, and 3 isodesmic reactions were designed to confirm their thermodynamic stability. What we found is that the 5‐membered‐ring endocyclic o‐oxygen stabilizes the benzyl carbocation 3 less than the acyclic o‐oxygen stabilizes the benzyl carbocation 1 in gas phase because of ring strain and through‐bond induction. However, the high solvation energies of the 5‐membered‐ring endocyclic o‐oxygen benzyl carbocation 3 not only offset the destabilizing effects of ring strain and through‐bond induction but also make it even more stable than the acyclic o‐oxygen benzyl carbocation 1 in polar solvents like acetonitrile, DMSO, and water.     

苯甲醇分子HOMO和N-HOMO轨道的电子动量谱学研究

利用第三代电子动量谱仪研究了苯甲醇(C_6H_5CH_2OH)分子的最高占据轨道(HOMO)和次最高占据轨道(N-HOMO)电子动量谱,给出了外价轨道的电离能谱信息.实验在非共面对称几何条件下完成,入射电子的能量为2400 eV加结合能.通过密度泛函方法计算得到了苯甲醇分子最高和次最高占据轨道的动量谱,理论与实验结果符合较好.     

Surface adsorption studies of benzyl bromide and bromobenzyl cyanide vapours on black phosphorene nanosheets – a first-principles perception

In this research, two-dimensional material, black-phosphorene nanosheets (Black-PNS) have been deployed as a sensing substrate for detecting two tear gas molecules, namely, benzyl bromide and bromobenzyl cyanide. The stability of black phosphorene sheet structure can be ensured by observing its formation energy, which is found to have ?3.895?eV/atom. Besides, the semiconducting nature of Black-PNS reinforces that it can be a potential base material to get deployed as a chemical sensor. The deviations in the density of states are noticed upon adsorption of benzyl bromide and bromobenzyl cyanide molecules on black phosphorene nanosheets. The energy of adsorption, energy gap variation and Bader charge transfer analysis are intended to investigate the assimilation properties of benzyl bromide and bromobenzyl cyanide on Black-PNS. The final results exhibit the possibility of using Black-PNS as a nanosensor substrate for lachrymator agents such as benzyl bromide and bromobenzyl cyanide.     

Insight into the synthesis procedure of Fe3+/TiO2-based photocatalyst applied in the selective photo-oxidation of benzyl alcohol under sun-imitating lamp

Fe³⁺/TiO₂/zeolite Y photocatalyst synthesized by using sonophotodeposition method was compared with photocatalysts prepared by simple photodeposition and sonodeposition methods in order to clarify the role of light irradiation and ultrasounds while they are used simultaneously. To gain an insight into the mechanism of this method a detailed characterization of the photocatalysts was carried out by means of the following techniques: UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, Mössbauer measurements and photocatalytic test reaction. Basing on the results from these techniques the chemical role of light and mainly mechanical role of ultrasound were observed. The selective photocatalytic oxidation of benzyl alcohol into benzaldehyde in liquid phase was a test reaction verifying the utility of the prepared materials. The best photocatalytic efficiency in this reaction was performed by photocatalyst synthesized using compilation of ultrasound energy with photoexcitation.     

DFT study the interaction of β‐cyclodextrin with benzyl azide and phenyl acetylene in synthesis of 1,2,3‐triazoles

The phenyl acetylene and benzyl azide cycloaddition reaction in water in the presence of β‐cyclodextrin (β‐CD) as a phase transfer catalyst (PTC) can get a better yield in a shorter time. The interaction between β‐CD and phenyl acetylene or benzyl azide plays an important role in this reaction. This paper studies the complexes of β‐CD with phenyl acetylene and benzyl azide using density functional theory (DFT) method. In order to find out the orientations of guests in the cavity of β‐CD, binding energy and deformation energy are investigated, and the calculated results are confirmed by ¹H nuclear magnetic resonance (¹HNMR). The data from single point energy indicate that the inclusion complexes can improve the solubilities of phenyl acetylene and benzyl azide in water. The ¹³C and ¹⁵N spectra show that the most obvious variation concentrates on C₆ and C₈ of phenyl acetylene and N₁₅ of benzyl azide in complexes. Mulliken charge and frontier orbital are employed for revealing the charge distribution. The effect of β‐CD is discussed in terms of the calculated parameters. Copyright © 2014 John Wiley & Sons, Ltd.     

饱和一元酸类化合物的拉曼光谱研究

通过实验检测获得了甲酸、乙酸、丙酸、丁酸四种-元酸的拉曼光谱.应用密度泛函理论对四种酸分子进行了模拟计算,计算结果与实验拉曼光谱吻合度较高,分别对四种酸的特征振动峰进行了详细的分析和振动归属.研究结果表明,甲酸的拉曼光谱与其他三种酸差异较大;乙酸、丙酸和丁酸的拉曼光谱具有一定的相似性,但主强峰位置和次强峰的强度存在着明...     

Effects of ultrasound on the formation of alpha-benzoylbenzyl cyanide from benzyl cyanide and alkylphenyl ketone from alpha-alkylbenzyl cyanide by potassium superoxide in the presence of crown ether

Ultrasound accelerates the formation of alpha-benzoylbenzyl cyanide and benzoic acid in the reaction of benzyl cyanide with potassium superoxide in the presence of 18-crown-6. Similarly, 4-methylbenzyl cyanide, 4-methoxybenzyl cyanide and 4-chlorobenzyl cyanide gave the corresponding alpha-(4-methylbenzoyl)-4-methylbenzyl cyanide, alpha-(4-methoxybenzoyl)-4-methoxybenzyl cyanide and alpha-(4-chlorobenzoyl)-4-chlorobenzyl cyanide in 25-43% isolated yields under the same reaction conditions. Benzoic, p-toluic, 4-methoxybenzoic and 4-chlorobenzoic acids were also formed in these reactions. No reaction was observed when the mixture was simply stirred. Reflux instead of sonication gave lower yields of the products. However, alpha-alkylbenzyl cyanide produced a high yield of the phenylalkyl ketones when stirred. Interestingly, the corresponding benzoic acid was not formed in these reactions. Possible mechanisms for the formation of alpha-benzoylbenzyl cyanide from benzyl cyanide and phenylalkyl ketones from alpha-alkylbenzyl cyanide are also proposed.     

The quest for a better system for evaluating pi‐electron substituent constant: a comparison of benzoic,acrylic and tria‐, penta‐, heptafulvene‐based carboxylic acids. A computational study

Carboxylic acids based on exo‐substituted tria‐, penta‐, heptafulvenes and ethylene (acrylic acids) were examined in order to determine if they are more sensitive to the substituent effect than benzoic acid – the system originally employed by Hammett. In order to accomplish this task, all possible structural isomers of benzoic acid, tria‐, penta‐ and heptafulvene‐based carboxylic acids, acrylic and methacrylic acids substituted by 13 substiuents (BH₂, CHO, CN, COCN, NO₂, CF₃, Me, Cl, F, OH, OMe, NH₂ and NMe₂) were optimized at the B3LYP/6‐311++G(d,p) level of theory, and Gibbs free energies of carboxylic group dissociation (ΔG_dis) were calculated. These energies were subsequently intercorrelated, and from the slopes of linear regressions, it was estimated which system is associated with greatest changes of ΔG_dis due to substitution and thus is most sensitive to the substituent effect. It was found that all fulvene‐based carboxylic acids have greater range of ΔG_dis change than benzoic acid, but the largest range of change was observed in the case of acrylic and methacrylic acids. The acrylic acid as the most sensitive system to substitution could replace benzoic acid for an improved version of substituent constant used to measure pi‐electron substituent effect. Copyright © 2013 John Wiley & Sons, Ltd.