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1.
Density functional theory B3LYP method with 6-31++G** basis was used to optimize the geometries of the ground states for 1,2,3-triazine-(H2O)n (n=1,2,3) complexes. All calculations indicate that the 1,2,3-triazine-water complexes in the ground states have strong hydrogen-bonding interaction, and the complex having a N…H-O hydrogen bond and a chain of water molecules which is terminated by a O…H-C hydrogen bond is the most stable. The H-O stretching modes of complexes are red-shifted relative to that of the monomer. In addition, the Natural bond orbit (NBO) analysis indicates that the intermolecular charge transfer between 1,2,3-triazine and water is 0.0222e, 0.0261e and 0.0273e for the most stable 1:1, 1:2 and 1:3 complexes, respectively. The first singlet (n, π*) vertical excitation energy of the monomer 1,2,3-triazine and the hydrogen-bonding complexes of 1,2,3-triazine-(H2O)n were investigated by time-dependent density functional theory.  相似文献   

2.
在B3LYP/6-31 G**水平上对1,2,3-三氮杂苯和水形成1∶1,1∶2和1∶3复合物的基态氢键结构进行几何优化和性质计算,结果表明复合物之间存在较强的氢键作用。氢键的形成使水分子中H-O键振动频率减小(红移)。NBO分析表明,最稳定的1∶1,1∶2和1∶3复合物发生分子间电荷转移总量分别为0.0222e,0.0261e和0.0273e。  相似文献   

3.
[Zn(DMF)6]H2SiW12O40·(CH3)2NH的合成,晶体结构及性质   总被引:1,自引:0,他引:1  
The title compound [Zn(DMF)6]H2SiW12O40·(CH3)2NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/m, a=2.0654(4)nm, b=1.3306(3)nm, c=1.3194(3)nm, β=119.59(3)°, V=3.1531(11)nm3, Dc=3.606Mg·m-3, Z=2, R=0.0462, Rw=0.0836. The title compound comprises of a [Zn(DMF)6]2+ unit, a polyanion and a free (CH3)2NH molecule. The ESR spectrum of the title compound shows that charge-transfer between organic groups and polyanion takes place under irradiation of the sunlight in solid state. The TG study of the title compound shows that it had four stages of the weight loss, and the increase of the de-composition temperature for the polyanion shows that the stability of the polyanion was enhanced due to the influence of Zn2+ ion. CCDC:175866.  相似文献   

4.
以α-H6P2W18O62·nH2O,Y2O3,DMSO(二甲亚砜)为原料合成了Dawson结构聚金属氧酸盐有机-无机复合物[{Y(DMSO)5(H2O)3}{Y(DMSO)8}][P2W18O62]·2DMSO·2H2O(1),化合物晶体属于单斜晶系,P21/c空间群,Mr=5803.06,a=1.7614(4)nm,b=3.1527(6)nm,c=2.1523(4)nm,β=90.40(3)°,V=11.963(4)nm3Dc=3.222g·cm-3,μ=18.566mm-1Z=4,F(000)=10464。由17342个可观测衍射点[I≥ 2σ(I)]用于精修所有的结构参数,得一致性因子R=0.0745,wR=0.1438。结构解析表明,化合物中两个Y3+离子的配位环境均为八配位的畸变双冠三棱柱构型。CV行为研究表明,标题化合物中阴离子(pH=5.5)存在五步还原过程,得电子数依次为1,1,1,1,2。化合物的IR光谱和X-射线衍射结果表明,固态条件下配阳离子与杂多阴离子之间存在较强的相互作用。  相似文献   

5.
The hydrogen bond structure and interaction energy on the ground state of pyridazine and water complex are studied with B3LYP and MP2 method. All calculations show that there are strong interactions for a hydrogen bond N…H-O and large red-shifts for the symmetric H-O stretching vibrational frequencies in the pyridazine and water complex. The first singlet 1(n, π ) and 1(π,π) vertical excitations of the monomer pyridazine and the hydrogen bond between a pyridazine molecule and a water molecule have been investigated with time-dependent density functional theory TDB3LYP method.  相似文献   

6.
李权 《中国科学B辑》2005,35(5):368-371
使用密度泛函理论B3LYP方法对三氮杂苯-水氢键复合物的基态结构与相互作用进行理论研究. 结果表明1,2,3-三氮杂苯-水, 1,2,4-三氮杂苯-水和1,3,5-三氮杂苯-水复合物基态分别具有Cs, Cs和C1对称性和强的氢键相互作用, 经基组重叠误差和零点振动能校正后的相互作用能分别为–17.83, –17.38和–13.55 kJ/mol. 三氮杂苯-水复合物中, N∙∙∙H—O氢键的形成使水的H—O对称伸缩振动频率明显红移. 同时使用含时密度泛函理论研究了三氮杂苯单体及其与水形成的氢键复合物的第一1(n, π*)激发态的垂直激发能.  相似文献   

7.
李权 《化学学报》2005,63(11):985-989
用密度泛函理论方法在B3LYP/6-31++G**水平上对1,2,4-三氮杂苯-(H2O)n (n=1, 2, 3)氢键复合物的基态进行了结构优化和能量计算, 结果表明复合物之间存在较强的氢键作用, 所有稳定复合物结构中形成一个N…H—O氢键并终止于弱O…H—C氢键的氢键水链的构型最稳定. 同时, 用含时密度泛函理论方法(TD-DFT)在TD-B3LYP/6-31++G**水平上计算了1,2,4-三氮杂苯单体及其氢键复合物的单重态第一1(n, π*)垂直激发能.  相似文献   

8.
用直接法培养了配合物[Co(H2O)6]·(Hnip)2·(H2nip)2·(DMA)2·(H2O)8(DMA=CH3NHCH3)的晶体并用X射线单晶衍射,元素分析和傅里叶变换红外光谱进行了表征。该晶体属于三斜晶系,P-1空间群,晶胞参数为a=0.7012(1)nm, b=1.1378(2) nm, c=1.6612(3) nm, α=84.92(3)º, β=85.19(3)º,γ=85.91(3)º。晶胞体积V=1.3128(5) nm3, Z=1, 理论密度Dc=1.573 g/cm3. 最终R因子[I>2σ(I)]为: R1=0.0279,wR2=0.0765; 所有衍射点的R因子为: R1=0.0327, wR2=0.0806.衍射结果表明,在晶体结构中两个Hnip分子,两个H2nip分子,两个DMA分子和八个水分子通过氢键和π-π堆积作用连接到每个Co配位八面体中心上。对配合物进行了DSC和TG-DTG热分析,根据热分析结果推测得到配合物的热分解机理,并且用Kissinger,Ozawa,积分法和微分法确定了最可能的动力学模型函数。  相似文献   

9.
本文首次报道三元体系Cu(NO3)2-CO(NH2)2-H2O(30℃)和La(NO3)3-CO(NH2)2-H2O(25℃)的等温溶度及饱和溶液、折光率,绘制相应的溶度图及折光率-组成图。体系中发现有组成为Cu(NO3)2·4CO(NH相似文献   

10.
A new polymer azido-bridged copper(II) complex [Cu4(En)21,1-N3)41,1,1-N3)21,3-N3)2] n (I) (En = ethylenediamine) has been synthesized and crystallography characterized. Complex I shows one-dimensional coordination polymeric structure based on a tetranuclear cluster unit [Cu4(En)21,1-N3)41,1,1-N3)21,3-N3)2], in which the azido ions display three different bridging modes.  相似文献   

11.
The hydrogen bonding structure and many‐body interactions between 1,3,5‐triazine (1,2,4‐triazine) and three water molecules are studied using the density functional theory (DFT) B3LYP method and 6‐31++G** basis set. Various structures of 1,3,5‐triazine–(water)3 and 1,2,4‐triazine–(water)3 complexes are investigated, and the seven and eight stable structures are reported for 1,3,5‐triazine–(water)3 and 1,2,4‐triazine–(water)3, respectively. Many‐body analysis is also carried out to obtain relaxation energy and many‐body interaction energy (two‐, three‐, and four‐body), and the most stable conformer has the basis set superposition error corrected interaction energy of ?92.09 and ?99.53 kJ/mol. The two‐ and three‐body interactions have significant contribution to the total interaction energy, whereas the relaxation energy, four‐body interactions are very small for 1,3,5‐triazine–(water)3 and 1,2,4‐triazine–(water)3 complexes. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007  相似文献   

12.
Structural properties and energetics for the optimized carbon monoxide cyclic oligomers are analyzed at the correlated ab initio second‐order Møller–Plesset (MP2) and density functional methods (B3LYP and mPW1PW), using Dunning's cc‐pVXZ (X = D, T, Q) basis set, augmented with diffuse functions. Many‐body interactions of the stable carbon monoxide cyclic oligomers, (CO)4 and (CO)5 are computed at the MP2/aug‐cc‐pVTZ level. Contributions of two‐ to five‐body terms to each of these oligomers for their interaction energies, including corrections for basis set superposition error (BSSE) are investigated by using function counterpoise and its generalized version. It has been found that three‐body terms are attractive in nature and essential in order to describe the cooperative effects in the stable cyclic CO oligomers. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005  相似文献   

13.
Two novel complexes [Cu L 2(MeOH)] ( 1 )and [Ag2 L (H L )2(MeOH)] ( 2 ) ( L = 5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐carboxylic acid) were synthesized and characterized by elemental analysis, IR and X‐ray diffraction. Complex 1 is a mononuclear structure; the molecules were assembled into an infinite 2–D supramolecular by the C–H···O weak interactions. Complex 2 is a centrosymmetric dinuclear structure with bis(unidentate) carboxylato co‐ordination mode, and the molecules were assembled into 2–D layers by C–H···O and O–H···O weak interactions.  相似文献   

14.
15.
An iridium(III) complex comprising three different cyclometalated phenylpyridine‐based ligands was designed and synthesized. Interestingly, mixed‐ligand complexes could be obtained by using a simple and straightforward procedure. A tris(heteroleptic) IrIII complex was obtained as a mixture of stereoisomers that could not be separated. Photophysical properties of the tris(heteroleptic) complex was investigated by UV/VIS absorption and luminescence spectroscopy, and compared with those of the parent homoleptic complexes. Modelling by time‐dependent density functional theory (TD‐DFT) was also performed to elucidate the nature and the location of the excited state, and to support the experimental results.  相似文献   

16.
A convenient method for one‐pot two‐step 1,3‐dipolar cycloadditon reaction of arylboronic acid, sodium azide followed with terminal alkynes in the presence of 2‐pyrrolecarbaldiminato‐Cu(II) complexes catalyst is reported. Various 1‐aryl‐1,2,3‐triazoles were prepared in 63%–97% yields in water at 30°C without any additives and avoiding the isolation of unstable aryl azides.  相似文献   

17.
The reaction of 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one (AMTTO, 1 ) with silver nitrate in methanol led to the dimeric complex {[(AMTTO)2Ag]NO3}2 ( 2 ). 2 was characterized by elemental analyses and IR spectroscopy as well as by X‐ray structure analysis. Crystal data for 2 at ?80 °C: crystal system orthorhombic, space group P212121 with a = 1043.6(1), b = 1329.6(1), c = 2358.4(1) pm, Z = 8 and R1 = 0.037. The cation possesses a highly distorted linear coordination sphere in the solid state.  相似文献   

18.
In the title compound, [Cu(C7H3N2O4)(C4H5N2)(H2O)], (I), pyridine‐2,6‐dicarboxylate (pydc2−), 2‐aminopyrimidine and aqua ligands coordinate the CuII centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square‐pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc2− ligand. Because of the presence of Cu...Xbridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the CuII centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond‐order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.  相似文献   

19.
The title compound, [Zn(SiF6)(C12H8N2)2]·CH3OH, contains a neutral heteroleptic tris‐chelate ZnII complex, viz. [Zn(SiF6)(phen)2] (phen is 1,10‐phenanthroline), exhibiting approximate molecular C2 point‐group symmetry. The ZnII cation adopts a severely distorted octahedral coordination. As far as can be ascertained, the title complex represents the first structurally characterized example of a ZnII complex bearing a bidentate‐bound hexafluorosilicate ligand. A density functional theory study of the isolated [Zn(SiF6)(phen)2] complex was undertaken to reveal the influence of crystal packing on the molecular structure of the complex. In the crystal structure, the methanol solvent molecule forms a hydrogen bond to one F atom of the hexafluorosilicate ligand. The hydrogen‐bonded assemblies so formed are tightly packed in the crystal, as indicated by a high packing coefficient (74.1%).  相似文献   

20.
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