胺(或氨) - CHCl3系CT复合物密度泛函法研究

报道对氨(NH3母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCl3)形成的系列复合物的理论研究结果。把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE)。探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等,结果表明,形成复合物的稳定性次序为NH3－CHCl3(Ⅰ)>CH3NH2-CHCl3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ)。形成复合物的过程包含着电荷转移。该系列复合物的稳定性与电荷转移量、前线轨道能量差△εL-H及广义H键距离良好的线性关系,与结合点的电荷布居也有密切的关系,复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果。计算结果能较好地解释有关的实验现象和规律。     

胺(或氨)一CHCI3系CT复合物密度泛函法研究

报道对氨(NH3,母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCL3)形成的系列复合物的理论研究结果．把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE).探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等.结果表明,形成复合物的稳定性次序为NH3-CHCl3(Ⅰ)>CH3NH2-CHCL3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ).形成复合物的过程包含着电荷转移.该系列复合物的稳定性与电荷转移量、前线轨道能量差ΔεL-H及广义H键距离有良好的线性关系,与结合点的电荷布居也有密切的关系.复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果.计算结果能较好地解释有关的实验现象和规律.     

芳香氮化物-CHCl3系列复合物密度泛函法研究

报道对芳香氮化物吡咯(C4H5N)、苯胺(C6H5NH2)、对位氯代吡啶(C5H4NCl)、吡啶(C5H5N)及吡咯负离子(C4H4N-)与三氯甲烷(CHCl3)形成的系列弱作用复合物的理论计算结果.把复合物看作是一个超分子,在密度泛函B3LYP/6-311G(d,p)的水平上进行计算,探讨该系列复合物的稳定性规律、电荷转移及主要几何参数变化等规律.计算结果表明:此类芳香氮化物与三氯甲烷(CHCl3)可形成一系列弱化学作用复合物,特别是带负电荷的芳香氮化物可与CHCl3形成较稳定的复合物.形成复合物的过程包含着电荷转移,该系列复合物的稳定性与广义H键距离的变化规律相一致,与电荷转移量的变化规律大体一致.     

苯酚-酰胺系列氢键复合物从头计算研究

运用G94W量子化学程序包,在HF/6-31G基组水平上对酰胺(DMF,DMA,HCONH2,HCONHCH3andCH3CONH2)与苯酚形成的系列氢键复合物(看作超分子)进行从头计算研究。根据计算结果探讨复合物的稳定性、施体和受体间的电荷转移及几何参数变化等规律。结果表明苯酚与上述一系列酰胺都可形成稳定的氢键复合物,其稳定性次序为CH3CONH2～HCONHCH3＞HCONH2＞DMA＞DMF。结果还表明形成氢键复合物的过程包含着电荷转移,电荷由供体酰胺转移到受体苯酚中,酰胺中C=O键长和苯酚中的O-H键长都明显有规律性地变长。计算结果与实验规律相符。     

三硝基苯-对位取代苯酚负离子荷移复合物从头算研究

运用G94W量子化学程序,在HF/3-21G基组水平上对三硝基苯-对位取代苯酚(取代基:CH~3O-,CH~3-,Cl-)负离子的电荷转移复合物进行从头计算。把电荷转移复合物看成一个超分子,研究该系列复合物的稳定性、电荷转移及几何构型等规律。计算结果表明,苯酚负离子供电中心O沿一倾角指向三硝基苯中的任意相邻两个硝基之间的C位置上,复合物的稳定性按对位取代苯酚取代基CH~3O-,CH~3-,Cl-的次序减小,与实验规律相一致。计算结果还表明,形成该系列复合物具有明显的电荷转移,其稳定性与电荷转移量有关等。     

[(CH3)2NH2]3[NSiMo12O40]·2DMF·4H2O的合成和晶体结构

电荷转移盐;[(CH3)2NH2]3[NSiMo12O40]·2DMF·4H2O的合成和晶体结构     

螺桨烷型分子BX[(CH_2)_n]_3和BX(CH_2)[CH(CH_2)_nCH](X=N,P)的结构和性质

采用密度泛函理论(DFT)研究了螺桨烷型分子BX[(CH2)n]3和BX(CH2)[CH(CH2)n CH](X=N,P;n=1-6)的结构、稳定性、化学键和电子光谱性质.计算结果表明这些分子都是稳定的.BX[(CH2)n]3(X=N,P;n=1-6)的最高占据分子轨道(HOMO)和最低空分子轨道(LUMO)之间的能隙均大于5.20 eV,其中BN[CH2]3和BP[CH2]3的能隙超过7.0 eV,与C5H6的能隙(7.27 eV)很接近,BX(CH2)[CH(CH2)n CH](X=N,P;n=1-6)的能隙在6.80 eV左右.所研究分子能量的二阶差分表明BN[(CH2)3]3、BP[(CH2)4]3及BX(CH2)[CH(CH2)2CH](X=N,P)是最稳定的.BX[(CH2)n]3的Wiberg键级表明除了BN[(CH2)n]3(n=2和6)中不存在B―N键,其它化合物中B和N均形成了化学键,BP[(CH2)n]3中除了BP[(CH2)2]3不存在B―P键,其它的均存在.电子密度的拓扑分析表明N―B键属于离子键,而P―B键具有共价键特征.BX[(CH2)n]3(X=N,P)的第一垂直激发能分别在191.1-284.8 nm和191.8-270.1 nm之间,BX(CH2)[CH(CH2)n CH](X=N,P)的第一垂直激发能分别在190.5-199.7 nm和209.0-221.3 nm之间.     

分子CH_3NH=B:的结构及重排反应的理论研究

采用量子化学中的从头计算方法, 在MP2/6-31G(d,p)水平上研究了不饱和硼烯CH3NH=B:的结构及重排反应机理。结果表明, CH3NH=B:的单线态结构比三线态结构稳定, 该分子的基态是单线态。分子CH3NH=B:可以发生3种不同的重排反应。本文找到了这3种重排反应的过渡态, 并详细计算了不饱和硼烯CH3NH=B:重排反应的动力学函数, 据此讨论了不饱和硼烯CH3NH=B:的稳定性问题。     

两个基于[SMo_(12)O_(40)]~(2-)和冠醚基超分子阳离子的无机-有机杂化晶体的合成及晶体结构（英文）

以18-冠-6和4-碘-苯铵盐,二苯并30-冠-10和3-氟-4-氯-苯铵盐为超分子阳离子构建单元,分别引入到Keggin型[SMo_(12)O_(40)]~(2-)中,使用H管扩散法和溶剂挥发法合成了无机-有机杂化材料[(4-I-Anis)([18]crown-6)]2[SMo12O40]·CH3CN (1)和[(3-F-4-Cl-Anis)2(DB[30]crown-10)][SMo12O40]·2CH3CN (2)(4-I-Anis=4-碘-苯铵盐;3-F-4-Cl-Anis=3-氟-4-甲基苯铵盐;DB[30]crown-10=二苯并30-冠-10)。通过红外光谱、元素分析、热重分析、固态漫反射光谱和X射线单晶结构分析对化合物进行了表征。结构分析表明,晶体1和2通过非共价键自组装作用构建而成,冠醚基超分子阳离子是通过N-H…O氢键作用形成。晶体1中,在bc平面,每个[SMo_(12)O_(40)]~(2-)多酸阴离子被6个超分子阳离子(4-I-Anis)([18]crown-6)围绕,形成六边形的结构;晶体2中,在bc平面,每个[SMo_(12)O_(40)]~(2-)多酸阴离子被4个大的超分子阳离子(3-F-4-Cl-Anis)2(DB[30]crown-10)围绕,形成四边形的结构。热重分析表明,氢键在维持晶体1和2的稳定性上起着主要的作用。固态漫反射光谱表明,[SMo_(12)O_(40)]~(2-)和冠醚基超分子阳离子之间存在电荷转移作用。     

分子CH3NH=B：结构及重排反应的理论研究

采用量子化学中的从头计算方法，在MP2／6—31G(d，p)水平上研究了不饱和硼烯CH3NH=B：的结构及重排反应机理。结果表明，CH3NH=B：的单线态结构比三线态结构稳定，该分子的基态是单线态。分子CH3NH=B:可以发生3种不同的重排反应。本文找到了这3种重排反应的过渡态，并详细计算了不饱和硼烯CH3NH=B：重排反应的动力学函数，据此讨论了不饱和硼烯CH3NH=B：的稳定性问题。     

Synthesis of some derivatives of 3-amino-3-desoxyerythrose and 3-amino-3-desoxy-D-3-erythrose

The synthesis of derivatives of 3-amino-3-deoxy-L-erythrose by LAH or LAD reduction of the oxime of 1,2-O-isopropylidene α-L -glycero-tetros-3-ulofuranose is described.     

Synthesis of γγγ-trifluorocarbonyl compounds

γγγ-Trifluorocarbonyl compounds are easily obtained in a good yield by introduction of the 1,1,1-trifluoroethyl moiety (CF₃-CH₂-) on the -methylene group of a ketone.     

Freezing the polarization of CH3NH3PbI3 and CH3NH3PbI3-xClx perovskite films

Thin films of methylammonium lead halides, CH₃NH₃PbI₃ and CH₃NH₃PbI_3-xCl_x, were deposited onto symmetrical microstructured electrode arrays of gold or platinum on Si/SiO₂ wafers. Polarization studies were carried out on perovskite films under vacuum in the dark. For poling, a constant voltage was applied to the samples while the temperature was cycled between 295 K and 4 K. The measured current densities depending on the temperature showed distinct characteristics relating strongly to the crystal phase and the dielectric properties of the perovskite films. Voltage sweeps were carried out at different scan rates at specific temperature intervals after poling. The polarization of the films due to the migration of iodide vacancies in direction of the blocking perovskite/metal interface was frozen almost up to room temperature. Charge carriers were only able to cross the blocking barrier and contribute to the current where the ions have accumulated during poling. All J-V curves showed hysteresis: inverted and regular hysteresis at room temperature and below, respectively. Inverted hysteresis originates from the slow accumulation of ions at the blocking barrier, while regular hysteresis arises from a distortion in the adjacent crystals which will be discussed.     

钙钛矿CH3NH3PbI3晶体的电化学

电化学方波伏安及循环伏安测量表明,钙钛矿CH₃NH₃PbI₃晶体在有机电解质中的氧化还原过程伴随着化学降解。该化学降解源于CH₃NH₃PbI₃晶体中铅离子的还原以及碘离子的氧化。通过电化学伏安法可以测定晶体的能带。     

Non-Isothermal Kinetics of the Decomposition Reaction of Cluster [Ag3WS3Br]（PPh3）3 and [Cu3WS3Br]（PPh3）3

The thermal behaviors of clusters [Ag3WS3Br](PPh3)3 and [Cu3WS3Br](PPh3)3 (PPh3=triphenyl phosphine) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC and EDS techniques. The results showed that the evolution of PPh3 generally proceeded before the release of the other moiety in one or two step-mode. The mechanisms, the kinetic and the thermodynamic parameters for decomposition of PPh3 of both clusters were determined and calculated by jointly using several methods, which showed that its evolution was controlled by Avrami-Erofeev equation. The results also showed that there was no new stable phase composed of W-Ag(Cu)-S-Br after release of organic moiety PPh3 and that CVD method was not applicable to their further processing.     

Addition of NH3 to Al3O3-

Recent computational studies on the addition of ammonia (NH3) to the Al3O3- cluster anion [A. Guevara-Garcia, A. Martinez, and J. V. Ortiz, J. Chem. Phys. 122, 214309 (2005)] have motivated experimental and additional computational studies, reported here. Al3O3- is observed to react with a single NH3 molecule to form the Al3O3NH3- ion in mass spectrometric studies. This is in contrast to similarly performed studies with water, in which the Al3O5H4- product was highly favored. However, the anion PE spectrum of the ammoniated species is very similar to that of Al3O4H2-. The adiabatic electron affinity of Al3O3NH3 is determined to be 2.35(5) eV. Based on comparison between the spectra and calculated electron affinities, it appears that NH3 adds dissociatively to Al3O3-, suggesting that the time for the Al3O3-NH3 complex to either overcome or tunnel through the barrier to proton transfer (which is higher for NH3 than for water) is short relative to the time for collisional cooling in the experiment.