COS与O2反应机理的理论研究

用量子化学密度泛函理论 (DFT)方法 ,对 COS与 O2的反应进行了理论研究 ,在 UB3LYP/6-31G* , UB3LYP/6-311 G**计算水平上 , 优化了反应势能面上各驻点(反应物、产物、中间体和过渡态)的几何构型 , 在 UB3LYP/6-31G*水平上通过内禀反应坐标( IRC)计算和振动分析 , 对过渡态进行了确认 , 并确定了反应机理. 研究结果表明 , 反应主要产物为 CO2和 SO.     

Reactivity of Tourmaline by Quantum Chemical Calculations

ZnAb initio calculations on reactivity of tourmaline were performed using both Gaussian and density function theory discrete variation method （DFT-DVM）. The HF, B3LYP methods and basis sets STO-3G（3d,3p）,6-31G（3d,3p） and 6-311＋＋G（3df,3pd） were used in the calculations. The experimental results show energy value obtained from B3LYP and 6-31＋＋1G（3df,3pd） basis sets is more accurate than those from other methods. The highest occupied molecular orbital （HOMO） of the tourmaline cluster mainly consists of O atom of hydroxyl group with relative higher energy level, suggesting that chemical bond between those of electron acceptor and this site may readily form, indicating the higher reactivity of hydroxyl group. The lowest unoccupied molecular orbital （LUMO） of the tourmaline cluster are dominantly composed of Si, O of tetrahedron and Na with relative lower energy level, suggesting that these atoms may tend to form chemical bond with those of electron donor. The results also prove that the O atoms of the tourmaline cluster have stronger reactivity than other atoms.     

溴化N-乙基吡啶离子液体分子结构和光谱性质的理论计算

研究采用密度泛函（DFF）B3LYP、B3PW91方法和从头算（abinitio）HF方法分别在6-31G＋（d,p）和6-311G＋（d,P）基组水平上计算了澳化N-乙基吡啶（[V．py]Br）离子液体的结构性质和光谱性质,通过自然键轨道（NBO）分析和振动分析,分别得到各原子的电荷分布和红外光谱,并对比了振动频率的...     

气相中Ni^＋与CS2反应的量子化学计算研究

采用密度泛函UB3LYP方法,在6-311＋＋G^＊＊基组水平上,研究了Ni^＋与CS2的反应体系。对其基态^2Ni^＋和激发态^4Ni^＋与CS2反应势能面上各驻点的几何构型进行了全优化与振动频率分析,并用内禀反应坐标（IRC）方法对过渡态进行了验证。对影响反应机理和反应速率的势能面交叉现象进行了讨论,运用Hammond假设和YOSHIZAWA等的内禀反应坐标垂直激发的计算方法找到了两个不同电子态反应势能面上的交叉点。计算结果表明,C—S键的活化遵循插入消去机理,最有利的反应通道为^2Ni＋^1CS2→^2IM1→^2TS12→CP1→^4IM2→^2NiCS^＋^3S。     

氧原子对二甲基亚硝胺羟基化反应的机理研究

用量子化学密度泛函（DFT）方法,在B3LYP／6—31G＊＊水平下,研究了氧原子对二甲基亚硝胺（NDMA）羟基化的反应机理。结果表明,氧原子对NDMA甲基上CH键的直接氧化过程,比经单一三交叉点的反应路径要容易的多。反应势能面进一步说明,氧化方式下的羟基化反应是容易进行的放热反应;溶剂化效应和MP2／6—311G＊＊更高级别的计算,不改变其反应机理,只改变了活化能的大小。     

碱金属氧化物和硫化物分子结构的从头算研究

使用分子轨道从头算方法,对Li2O,Li2S,Na2O,Na2S分子的基态构型进行了理论研究,计算结果表明,在HF/6—3lG* 和MP2(fu)/6—31G* 水平上,Li2O,Li2S,Na2S分子优化结构出现明显的差异,电子相关修正在优化键角过程中起着重要的作用,考虑了电子相关修正后,Li2O,Li2S,Na2S 分子均呈现稳定的弯曲结构．Na2O分子考虑了电子相关修正后仍为线性结构．     

[Si,O,C,P]自由基的结构和生成路径

在密度泛函和从头算的理论下,研究了双重态[Si,O,C,P]自由基的结构和生成路径。在B3LYP/6-311G(d)水平下,计算得到13个异构体和15个过渡态。在QCISD/6-311G(d)水平下,环状结构的O-cCSiP5和两个弯曲的异构体OSiCP1和SiCPO3是动力学稳定的异构体。三个异构体的价键结构和异构体1和5可能的生成路径被讨论。预测的结构和生成路径对[Si,O,C,P]自由基将来的实验室制备和星际探测具有帮助作用。     

Theoretical Study on the C-H Activation in Decarbonylation of Acetaldehyde by NiL_2(L=SO_3CH_3) Using Density Functional Theory

Density functional theory calculations were carried out to explore the potential energy surface(PES) associated with the gas-phase reaction of Ni L2(L=SO3CH3) with acetone. The geometries and energies of the reactants, intermediates, products and transition states of the triplet ground potential energy surfaces of [Ni, O, C2, H4] were obtained at the B3LYP/6-311++G(d,p) levels in C,H,O atoms and B3LYP/ Lanl2 dz in Ni atom. It was found through our calculations that the decabonylation of acetaldehyde contains four steps including encounter complexation, C-C activation, aldehyde H-shift and nonreactive dissociation. The results revealed that C-C activation induced by Ni L2(L=SO3CH3) led to the decarbonylation of acetaldehyde.     

CH3CH2F与O（3P）反应机理的量子化学研究

用量子化学从头算MP2(full)/6-311G(d,p)方法研究了CH3CH2F与O(3P)反应的反应机理.在QCISD(T)/6-311++G(d,p)水平上精确计算了各反应物种的能量.结果表明:CH3CH2F与O(3P)反应共存在4类反应9个反应通道,分别为抽提氢反应,消氢反应,碳碳键断裂反应和消氟化氢反应,抽提氢反应为主反应通道.     

气相中二氧化铬与乙烯反应机理的理论研究

用密度泛函B3LYP／6—311＋＋G（3df,3pd）//6—311G（2d,p）法研究了CrO2＋（2A1／^4A″）＋C2H4生成P1[Cr（OCH2）^＋（^2A″／^4A″）＋CH2O]和P2[CrO^＋（^2∑g/^4∑g）＋C2H2O]的气相反应,重点对影响反应机理和反应速率的势能面交叉现象进行了讨论,并运用Hammond假设和Yoshizawa等的内禀反应坐标单点垂直激发计算的方法大致确定了势能面交叉点（crossing point（CP））或势能面交叉缝（crossjng seam）的位置。研究结果表明,CrO2^＋活化乙烯C-C键是一个[2＋2]类型反应,整个反应经历了重排过程。     

BS^x分子（离子）基态的结构与势能函数

应用B3LYP,B3P86方法以及6-311g,6-311g（d,p）,6-311＋＋g（df）,6-311＋＋g（3df）,aug-cc-pvdz,aug-cc-pvtz,D95（d）多种基组,对BS分子,BS＋及BS-离子基态进行几何优化和单点能扫描计算.用最小二乘法,拟合得到BSX（X=-1,0,＋1）分子（离子）基态的Murrell-Sorbie势能函数.由于BS分子计算结果与实验值符合得很好,首次给出了BSX（X=-1,0,＋1）分子（离子）的势能函数,为BSX（X=-1,0,＋1）分子（离子）的反应动力学提供了理论依据.     

密度泛函理论研究CH_3Cl与Cl~(4/)的亲核取代反应

用DFT理论的B3LYP/6 31 1 + +G 水平上对反应Cl- +CH3Cl→ClCH3+Cl-的电子转移的振动光谱进行研究。此反应包括旧键断裂 ,新键生成以及分子间的电子转移。分析了反应物 ,前驱配合物 ,过渡态 ,后继配合物和产物的振动频率及振动模式。它们之间的关系和变化验证了键的断裂、键的生成及电子转移过程     

Stability, detonation properties and pyrolysis mechanisms of polynitrotriprismanes C6H6-n（NO2）n （n=1-6）

To further test whether polynitriprismanes are capable of being potential high energy density materials (HEDMs), extensive theoretical calculations were carried out to investigate on a series of polynitrotriprismanes (PNNPs): C₆H_6−n (NO₂) _n (n=1−6). Heats of formation (HOFs), strain energies (SE), and disproportionation energy (DE) were obtained using B3LYP/6-311+G(2df, 2p)//B3LYP/6-31G* method by designing different isodesmic reactions, respectively. Detonation properties of PNNPs were obtained by the well-known KAMLET-JACOBS equations, using the predicted densities (ρ) obtained by Monte Carlo method and HOFs. It is found that they increase as the number of nitro groups n varies from 1 to 6, and PNNPs with n≥4 have excellent detonation properties. The relative stability and the pyrolysis mechanism of PNNPs were evaluated by the calculated bond dissociation energy (BDE). The comparison of BDE suggests that rupturing the C-C bond is the trigger for thermolysis of PNNPs. The computed BDE for cleavage of C-C bond (88.5 kJ/mol) further demonstrates that only the hexa-nitrotriprismane can be considered to be the target of HEDMs.     

甲烷水合物的热力学性质

利用密度泛函理论对甲烷水合物的两种构型(51262和512)进行了热力学性质的理论研究。在B3LYP/6-31G**的水平下对甲烷水合物进行全优化、热力学性质的计算以及势能曲线的扫描。通过计算得知,笼内有一个甲烷分子的构型可以在自然界中稳定存在。热力学性质分析表明,51262笼中有一个甲烷分子比512笼中有一个甲烷分子更稳定,甲烷水合物的最佳保存热力学条件为190K、200 MPa。频率分析得知,在51262笼中,甲烷分子碳氢键的伸缩振动强度比在512笼中弱,这与键长的趋势相一致。通过扫描势能曲线发现,甲烷分子在512笼中的行为是受限的,这与甲烷分子碳氢键的伸缩振动频率相一致。     

Correlation between Structure and Thermal Properties of N-vinyl-3-alkylimidazolium Magnetic Ionic Liquids

Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate(III) magnetic ionic liquids(MILs) on thermal properties was investigated. Using Gaussian09/B3 PW91/6-311 G(2d, p) density functional methods, the microstructure of the MILs were analyzed. With differential scanning calorimeter(DSC) and thermogravimetric analysis(TGA), the thermal properties of the MILs were performed. The results showed that the interaction energies of ion pairs decreased, the crystallization temperature increased first and then decreased, and the surfusion first decreased and then increased with the elongation of the alkyl chain length on cation; with the increase of Br atom, the interaction energies of ion pairs increased; the interaction energies of ion pairs increased in the MILs with the same cation or anion, the nature of polarity of MILs increased and the melting point rose; as the cation or anion in MILs had a smaller size, it could have the solidsolid transition temperature. The results indicated that the decomposition temperature with the same type of MILs increased with the interaction energies of ion pairs. The interaction energy of ion pairs can be used to illuminate the correlation between the thermal properties and the structure of MILs. ILs possesses the properties of macromolecular.     

MgSO4—H2O体系高温结晶动力学研究

研究了１８０℃,硫酸镁的浓度为２０％的过饱和溶液的结晶动力学规律。结果表明,该体系只析出一水硫酸镁一种固相,利用优化配合Ｒｕｎｇｅ－Ｋｕｔｔａ微分方程组数值解法对实验数据进行处理,拟合得到结晶过程的动力学方程为：－ｄＣ／ｄｔ＝０．１１８,结晶过程受晶体生长控制。     

CO和O2与Aum簇相互作用的DFT研究（II）

采用B3LYP／／LAN2Dz和相对论赝势ECP对Au、6．311＋G^＊基组对C和O水平下,对02和CO＋02在Aum（n=3—5,m=0,±1）上发生单分子和双分子吸附的可能结构进行全优化和振动分析。获得了Aun（O2）^m和AunCO（O2）^m最低能量结构。通过对其结构和能量分析,给出了O2和CO＋O2与AuO相互作用性质和变化规律。结果表明O2在Au;上吸附能均较小而难形成稳定吸附,其反应活性在Aun上呈奇偶交替现象,O2仅在偶数Au4-上发生有效吸附。CO和O2在Au2和Aun（n=4～5）上无明显协同吸附,二者在Au4-上存在明显协同吸附效应,而在Au,和Au3-上仅有弱协同效应。Au。（CO）0f（n=3～5）中C-O和O-O键长增大、相应伸缩振动频率降低,表明Au．-对C-O和O—O键有活化作用,它们可能是CO低温氧化的活性组分。可以推断,能够稳定阴离子Au簇的氧化物载体对提高氧化物负载纳米Au催化剂催化活性有利。     

胸腺嘧啶与碱土金属离子形成复合物的振动分析

采用密度泛函方法的B3LYP泛函,在6-311+G(2df,2p)基组水平上计算了胸腺嘧啶与碱土金属离子形成稳定复合物的振动情况.发现当离子与胸腺嘧啶分子的各互变异构体形成复合物时,分子内部振动会发生改变,这主要是由于离子参与分子的振动,改变了振动质量因素和力常数.     

干法脱硫过程中CaO与SO2反应机理研究

在B3LYP/6-311＋＋G（d,p）水平上研究CaO在干法脱硫过程中与SO2反应的微观机理,优化得到了反应物、中间体、过渡态、产物构型和相应的能量值。结果表明,CaO与SO2反应首先是无势垒络合形成具有链状结构的中间体O1SO2CaO3,随后链端的O1和O3原子分别进攻链中的钙原子和硫原子,经两条路径生成产物CaSO3;比较发现,两条路径对产物生成的贡献大致相等,且低温有利于产物亚硫酸钙的生成,这与低温固硫效率高的工业脱硫实际工艺相符合。     

4-(1-哌嗪)类香豆素化合物体外抗血小板凝结活性的QSAR模型研究

采用Chem3D软件自带的分子力学MM2模块对17种4-(1-哌嗪)类香豆素化合物进行几何结构预优化。通过DFT中B3LYP方法在6-31G(d,p)基组水平上对其进行几何构型的全优化。提取Gaussian以及HyperChem软件中相关的量子化学参数并进行相关分析以及回归分析,构建了最优的QSAR模型:lg(1/IC50)=-104.3(±35.203)×ELUMO-0.003(±0.001)EHF-25.549(±7.278),n=11,R=0.821,R2=0.674,R2(cv)=0.593,σ=0.257,F=18.028。