Crystal Structure and Dodecaaminium Didecavanadate Dodecahydrate

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＤｏｄｅｃａａｍｉｎｉｕｍＤｉｄｅｃａｖａｎａｄａｔｅＤｏｄｅｃａｈｙｄｒａｔｅ￥ＣｈｅｎｇＣｈａｎｇ－Ｚｈａｎｇ；ＳｈａｏＳｈｉ－Ｂａｏ；ＨｕａｎｇＸｉａｏ－Ｙｉｎｇ；ＬｉｎＺｈｏｕ－Ｂｉｎ（ＦｕｊｉａｎＩｎｓｔ...     

Synthesis，Crystal Structure of N－Salicylidene－o－aminobenzoic Acid Dipyridine Copper（Ⅱ） Monohydrate

Ｓｙｎｔｈｅｓｉｓ，ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＮ－Ｓａｌｉｃｙｌｉｄｅｎｅ－ｏ－ａｍｉｎｏｂｅｎｚｏｉｃＡｃｉｄＤｉｐｙｒｉｄｉｎｅＣｏｐｐｅｒ（Ⅱ）ＭｏｎｏｈｙｄｒａｔｅＬｉＳｈｕ－Ｌａｎ；ＬｉｕＤｅ－Ｘｉｎ；ＭｅｎｇＦａｎ－Ｑｉｎ；Ｚｈ...     

Crystal and Molecular Structure of Cyanuric Acid

ＣｒｙｓｔａｌａｎｄＭｏｌｅｃｕｌａｒＳｔｒｕｃｔｕｒｅｏｆＣｙａｎｕｒｉｃＡｃｉｄＣｈｅｎＣｈａｎｇ－Ｚｈａｎｇ；ＳｈｉＪｉａｎ－ＱｉｕＬｉｎＺｈｏｕ－Ｂｉｎ；ＧａｏＤｏｎｇ－Ｓｈｏｕ；ＨｕａｎｇＸｉａｏ－Ｙｉｎｇ；ＬｉＤｉｎｇ（ＦｕｊｉａｎＩｎｓ...     

Neutron Diffraction Study on Structure of α－LiIO_3 Single Crystal under DC Voltage

ＮｅｕｔｒｏｎＤｉｆｆｒａｃｔｉｏｎＳｔｕｄｙｏｎＳｔｒｕｃｔｕｒｅｏｆα－ＬｉＩＯ_３ＳｉｎｇｌｅＣｒｙｓｔａｌｕｎｄｅｒＤＣＶｏｌｔａｇｅＣｈｅｎｇＹｕ－Ｆｅｎ；ＹａｎｇＺｈｅｎ；ＣｈｅｎｇＺｈｉ－Ｘｕ；ＧｕｏＬｉ－Ｐｉｎｇ（ＣｈｉｎａＩｎｓｔｉ?..     

Synthesis and Structure of 4—Nitrobenzaldehyde Thiosemicarbazone

ＳｙｎｔｈｅｓｉｓａｎｄＳｔｒｕｃｔｕｒｅｏｆ４－ＮｉｔｒｏｂｅｎｚａｌｄｅｈｙｄｅＴｈｉｏｓｅｍｉｃａｒｂａｚｏｎｅＴｉａｎＹｕ－Ｐｅｎｇ；ＤｕａｎＣｈｕｎ－Ｙｉｎｇ；ＬｕＺｈｏｎｇ－Ｌｉｎ；ＹｏｕＸｉａｏ－Ｚｅｎｇ（ＣｏｏｒｄｉｎａｔｉｏｎＣｈｅ...     

Syntheses，Structures and Spectroscopic Properties of Mo（W）－Cu－S－Cluster Compounds with Dialkyldithiocarbamate Ligands

Ｓｙｎｔｈｅｓｅｓ，ＳｔｒｕｃｔｕｒｅｓａｎｄＳｐｅｃｔｒｏｓｃｏｐｉｃＰｒｏｐｅｒｔｉｅｓｏｆＭｏ（Ｗ）－Ｃｕ－Ｓ－ＣｌｕｓｔｅｒＣｏｍｐｏｕｎｄｓｗｉｔｈＤｉａｌｋｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅＬｉｇａｎｄｓＣａｏＲｏｎｇ；ＬｅｉＸｉｎ－Ｊｉ...     

Crystal Structures of O－Vanillin－semicarbazide and Salicylaldehyde－semicarbazide

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｓｏｆＯ－Ｖａｎｉｌｌｉｎ－ｓｅｍｉｃａｒｂａｚｉｄｅａｎｄＳａｌｉｃｙｌａｌｄｅｈｙｄｅ－ｓｅｍｉｃａｒｂａｚｉｄｅ￥ＬｉＳｈｕ－Ｌａｎ；ＬｉｕＤｅ－Ｘｉｎ；ＺｈｏｕＪｉａｎ－Ｈｕａ；ＭｅｎｇＦａｎ－Ｑｉｎ（Ｄｅｐａ...     

Synthesis and Electrical Properties of Some Carbonium－Metal－（DMIT）_2 Complexes

ＳｙｎｔｈｅｓｉｓａｎｄＥｌｅｃｔｒｉｃａｌＰｒｏｐｅｒｔｉｅｓｏｆＳｏｍｅＣａｒｂｏｎｉｕｍ－Ｍｅｔａｌ－（ＤＭＩＴ）２ＣｏｍｐｌｅｘｅｓＳｈｕＱｉｎｇＳＵＮ；ＰｅｉＪｉＷＵ；ＤａｏＢｅｎＺＨＵ（ＩｎｓｔｉｔｕｔｅｏｆＣｈｅｍｉｓｔｒｙ．Ｃｈｉｎｅ...     

Synthesis and X－ray Structure of Solvated Mono－cyclopentadienyl Samarium Dichloride（C_5H_5）SmCl_2（THF）_3

ＳｙｎｔｈｅｓｉｓａｎｄＸ－ｒａｙＳｔｒｕｃｔｕｒｅｏｆＳｏｌｖａｔｅｄＭｏｎｏ－ｃｙｃｌｏｐｅｎｔａｄｉｅｎｙｌＳａｍａｒｉｕｍＤｉｃｈｌｏｒｉｄｅ（Ｃ_５Ｈ_５）ＳｍＣｌ_２（ＴＨＦ）_３￥ＱｉａｎＣｈａｎｇ－Ｔａｏ；ＺｈｕＤｕｎ－Ｍｉｎｇ；ＳｕｎＪ...     

Structure Refinement of Samarium Tritellurides

ＳｔｒｕｃｔｕｒｅＲｅｆｉｎｅｍｅｎｔｏｆＳａｍａｒｉｕｍＴｒｉｔｅｌｌｕｒｉｄｅｓＣｈｉＬｉ－Ｓｈｅｎｇ；ＤｅｎｇＳｈｕｉ－Ｑｕａｎ；ＺｈｕａｎｇＨｏｎｇ－Ｈｕｉ（ＳｔａｒｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｔｒｕｃｔｕｒａｌＣｈｅｍｉｓｔｒｙ，Ｆｕ...     

2-(甲苯-4-磺酰胺基)-苯甲酸的晶体结构、光谱及热性质

报道了2-(甲苯-4-磺酰胺基)-苯甲酸(I)的元素分析和红外、核磁共振光谱性质并通过单晶X射线衍射确定了其晶体结构. 晶体属单斜晶系, 空间群为C2/c,晶胞参数为, a=2.7320(3) nm, b=0.85441(8) nm, c=1.17607(11) nm, α=90°, β=98.728(3)°, γ=90°, V=2.7135(5) nm3, Z=8. 晶体中分子单体通过N—H…O 和O—H…O氢键作用形成具有中心对称的二聚体, 且进一步通过两种不同的C—H…O 氢键和π…π作用形成超分子结构. 在不同的溶剂中, 化合物I的紫外吸收表现出明显的溶剂效应, 此外, 荧光光谱与DSC-TGA热重分析表明, 该化合物是一种耐热的荧光材料.     

氢转移反应HNCO+CH_x(x=1～3)的MP2和QCISD计算研究

在UMP2（FULL）/6-311（d,p）计算水平上,计算并讨论了碳氢自由基(CH_x) 和异氰酸（HNCO）发生氢转移反应位能面上驻点的结构和分子结构变化,并依据 UMP2的优化构型,进一步采用UQCISD（T）方法对反应途径上的驻点进行了单点能 量计算。研究指出,HNCO同CH_2,CH_3自由基反应时,氢转长期过程在分子间以新 的C-H键生成和旧的N-H键的断裂的协同方式进行,反应途径上均存在弱的氢键超分 子复合物;而HNCO和CH分子之间发生的氢转移反应机理是在反应剖面的反应物一边 生成一个较稳定的分子复合物HNJ（CH）CO,而后,在生成物一边又生成一个既有 热力学又有动力学稳定的复合物H_2CNCO。     

Theoretical study of the N-H…O red-shifted and blue-shifted hydrogen bonds

Theoretical calculations are performed to study the nature of the hydrogen bonds in complexes HCHO…HNO, HCOOH…HNO, HCHO…NH3, HCOOH…NH3, HCHO…NH2F and HCOOH…NH2F. The geometric structures and vibrational frequencies of these six complexes at the MP2/6-31+G(d,p), MP2/6-311++G(d,p), B3LYP/6-31+G(d,p) and B3LYP/6-311++G(d,p) levels are calculated by standard and counterpoise-corrected methods, respectively. The results indicate that in complexes HCHO…HNO and HCOOH…HNO the N-H bond is strongly contracted and N-H…O blue-shifted hydrogen bonds are observed. While in complexes HCHO…NH3, HCOOH…NH3, HCHO…NH2F and HCOOH…NH2F, the N-H bond is elongated and N-H…O red-shifted hydrogen bonds are found. From the natural bond orbital analysis it can be seen that the X-H bond length in the X-H…Y hydrogen bond is controlled by a balance of four main factors in the opposite directions: hyperconjugation, electron density redistribution, rehybridization and structural reorganization. Among them hyperconjugation has the effect of elongating the X-H bond, and the other three factors belong to the bond shortening effects. In complexes HCHO…HNO and HCOOH…HNO, the shortening effects dominate which lead to the blue shift of the N-H stretching frequencies. In complexes HCHO…NH3, HCOOH…NH3, HCHO…NH2F and HCOOH…NH2F where elongating effects are dominant, the N-H…O hydrogen bonds are red-shifted.     

Rapid and accurate evaluation of the binding energies and the individual N-H···O=C, N-H···N, C-H···O=C, and C-H···N interaction energies for hydrogen-bonded peptide-base complexes

The binding energies of thirty-six hydrogen-bonded peptide-base complexes, including the peptide backbone-ase complexes and amino acid side chain-base complexes, are evaluated using the analytic potential energy function established in our lab recently and compared with those obtained from MP2, AMBER99, OPLSAA/L, and CHARMM27 calculations. The comparison indicates that the analytic potential energy function yields the binding energies for these complexes as reasonable as MP2 does, much better than the force fields do. The individual N H…O=C, N H…N, C H…O=C, and C H…N attractive interaction energies and C=O…O=C, N H…H N, C H…H N, and C H…H C repulsive interaction energies, which cannot be easily obtained from ab initio calculations, are calculated using the dipole-dipole interaction term of the analytic potential energy function. The individual N H…O=C, C H…O=C, C H…N attractive interactions are about 5.3±1.8, 1.2±0.4, and 0.8 kcal/mol, respectively, the individual N H … N could be as strong as about 8.1 kcal/mol or as weak as 1.0 kcal/mol, while the individual C=O…O=C, N H…H N, C H…H N, and C H…H C repulsive interactions are about 1.8±1.1, 1.7±0.6, 0.6±0.3, and 0.35±0.15 kcal/mol. These data are helpful for the rational design of new strategies for molecular recognition or supramolecular assemblies.     

A new polymorph of methimazole: Single crystal and powder X-ray diffraction study

A new polymorph of 1-methyl-4-imidazoline-2-thione has been first discovered and studied by X-ray diffraction. The crystal of the new polymorph is monoclinic, the asymmetric part of the cell contains three independent molecules. In the crystal, the key compound is in the form of planar hydrogen-bonded dimers due to the interactions of the N-H…S type. The new modification is of an intensely yellow color in contrast to the previously known colorless forms, is characterized by a lower density but stronger hydrogen bonds; it is formed as a minor impurity to main triclinic polymorph.     

Synthesis and Crystal Structure of Bis{2-bromo- 4-chloro-6-[(2-isopropylammonioethylimino)-methyl]phenolato}bisthiocyanatozinc(Ⅱ)

A Schiff base zinc(Ⅱ) complex [Zn(C12H16BrClN2O)2(NCS)2] was prepared and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P with a = 8.414(1), b = 9.124(1), c = 22.212(3) (A), α = 79.177(2), β = 86.296(2), γ = 89.899(2)o, V = 1671.3(4) (A)3, Z = 2, Dc = 1.631 g/cm3, Mr = 820.79, λ(MoKα) = 0.71073 (A), μ = 3.444 mm-1, F(000) = 824, R = 0.0646 and wR = 0.1179. A total of 7371 unique reflections were collected, of which 3904 with I＞2σ(I) were observed. The complex crystallizes with two half-molecules per asymmetric unit and each mononuclear molecule is centrosymmetric. The Zn atom lying at the inversion centre is six-coordinated in a slightly distorted octahedral geometry by two phenolate O atoms and two imine N atoms from two Schiff base ligands, as well as two N atoms from two thiocyanate anions. In the crystal structure, the combination of π-π stacking interactions and intermolecular hydrogen bonds (N-H…Br, N-H…O, N-H…N, C-H…O, C-H…S and C-H…Cl) leads to a three-dimensional network.     

4-Amino-3-（p-chlorophenyl）-5-（p-methoxybenzyl）-4H-1,2,4-triazole：X-ray and DFT-calculated Structures

The title compound, 4-amino-3-(p-chlorophenyl)-5-(p-methoxybenzyl)-4H-1,2,4- triazole I , C16H15ClN4O), has been determined using X-ray diffraction techniques and the molecular structure has also been optimized at the B3LYP/6-31 G(d, p) level using density functional theory (DFT). The triazole ring exhibits dihedral angles of 41.61(15)o and 80.73(11)o with the phenyl rings. The molecules are linked principally by N–H…N hydrogen bonds involving the amino NH2 group and a triazole N atom, forming C(5) chains which are further linked to give a two-dimensional network of molecules. The N–H…N hydrogen bonding is supported by C–H…N hydrogen bond and C–H…π interaction. Intermolecular N–H…N and C–H…N hydrogen bonds produce R22(9), R44(10) and R44(20) rings.     

取代基对N—H…O＝C氢键三聚体中氢键强度的影响

使用MP2方法研究了氢键三聚体中N-H…O=C氢键强度,探讨了氢键受体分子中不同取代基对N-H…O=C氢键强度的影响.研究表明,不同取代基对氢键三聚体中N-H…O=C氢键强度的影响是不同的:取代基为供电子基团,氢键键长r(H…O)缩短,氢键强度增强;取代基为吸电子基团,氢键键长r(H…O)伸长,氢键强度减弱.自然键轨道(NBO)分析表明,N-H…O=C氢键强度越强,氢键中氢原子的正电荷越多,氧原子的负电荷越多,质子供体和受体分子间的电荷转移越多.供电子基团使N-H…O=C氢键中氧原子的孤对电子n(O)对N-H的反键轨道σ~*(N-H)的二阶相互作用稳定化能增加,吸电子基团使这种二阶相互作用稳定化能减小.取代基对与其相近的N-H…O=C氢键影响更大.     

Syntheses, Crystal Structures and Fluorescence Properties of Two Triazolyl Derivatives with Biphenyl Links

Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26（6）° in 1·H2O·HCl, while co-planar （0.00（7）°） in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl, C-H…Cl, C-H…O and π-π supramolecular interactions. The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.     

Treatment of hydrogen bonding within CNDO/2 and MINDO/3: CNDO/2H and MINDO/3H

A formalism has been developed to treat hydrogen-bonded A—H…?B systems within the CNDO /2 and the MINDO /3 methodologies. In this formalism the interactions are divided into three distinct classes; those between (a) two hydrogen-bonded atoms, (b) one hydrogen-bonded and non-hydrogen-bonded atom, and (c) two non-hydrogen-bonded atoms. The last class of interactions is treated solely by the existing CNDO /2 or MINDO /3 method. For A –H…?B systems, the core resonance integrals are individually parametrized depending upon the class of the interaction. Three types of A—H…?B systems have been thus far parametrized. Nine hydrogen-bonded dimers have been studied using the new formalism and the current CNDO /2 and the MINDO /3 methods. MINDO /3 predicts very large interatomic (A –B) distances for the equilibrium geometry, and relatively small stabilization values for the hydrogen-bond energies. CNDO/2 predicts the reverse. The new formalism for both CNDO /2 and MINDO /3 predicts accurate geometries as well as energies for all nine dimers. The new formalisms are called CNDO /2H and MINDO /3H. A general discussion of the nature of hydrogen bonding as exhibited by CNDO /2H and MINDO /3H is presented.