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1.
The dinuclear molecule of p‐(Ph3SnCH2SiMe2)2C6H4 adopts an ‘S’ conformation in the solid state, which is stabilized by C? H···π interactions. Distorted tetrahedra defined by C4 donor sets are found for the tin atoms. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
2.
The dinuclear molecule of p‐{[(Me3Si)2CH]Sn(Cl)2CH2SiMe2}2C6H4 is centrosymmetric and adopts an ‘S’ conformation that is stabilized by intramolecular C? H···π interactions. The tin atom exists within a distorted tetrahedron defined by a C2Cl2 donor set. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
3.
Andrei V. Afonin Igor A. Ushakov Alexander V. Vashchenko Dmitry E. Simonenko Andrei V. Ivanov Alexander M. Vasil'tsov Al'bina I. Mikhaleva Boris A. Trofimov 《Magnetic resonance in chemistry : MRC》2009,47(2):105-112
According to the 1H, 13C and 15N NMR spectroscopic data and DFT calculations, the E‐isomer of 1‐vinylpyrrole‐2‐carbaldehyde adopts preferable conformation with the anti‐orientation of the vinyl group relative to the carbaldehyde oxime group and with the syn‐arrangement of the carbaldehyde oxime group with reference to the pyrrole ring. This conformation is stabilized by the C? H···N intramolecular hydrogen bond between the α‐hydrogen of the vinyl group and the oxime group nitrogen, which causes a pronounced high‐frequency shift of the α‐hydrogen signal in 1H NMR (~0.5 ppm) and an increase in the corresponding one‐bond 13C–1H coupling constant (ca 4 Hz). In the Z‐isomer, the carbaldehyde oxime group turns to the anti‐position with respect to the pyrrole ring. The C? H···O intramolecular hydrogen bond between the H‐3 hydrogen of the pyrrole ring and the oxime group oxygen is realized in this case. Due to such hydrogen bonding, the H‐3 hydrogen resonance is shifted to a higher frequency by about 1 ppm and the one‐bond 13C–1H coupling constant for this proton increases by ~5 Hz. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
4.
合成了两个新的配合物CuLCl2•2EtOH(1) 和CoLCl2 (2) [L是( S , S )-1,2-二N-甲基苯并咪唑-1,2-二甲氧基-乙烷],并通过单晶X衍射确定它们的结构。配合物1中,L作为三齿[N, N, O]配体,而配合物2 中,L作为二齿[N, N]配体。这两个配合物共同的结构特点都是通过分子内氢键形成2维的格子结构,然后通过分子间的C-H···Cl型氢键和π–π堆积作用形成3维结构。 相似文献
5.
三氟甲磺酸被发现能够高效地活化(SP3)碳-氟键。因此,在其催化作用下,室温时含三氟甲基的芳香化合物与苯反应得到二苯甲酮类化合物。在同样的Brønsted 酸催化下,其中一些含三氟甲基的芳香化合物亦可发生分子内的芳基化反应,而此时分子间的芳基化受抑制。强的氢氟间的相互作用或氢键作用,被认为对该Brønsted 酸参与碳氟键活化的反应起了重要作用。 相似文献
6.
Andrei V. Afonin Igor A. Ushakov Alexander V. Vashchenko Evgeniy V. Kondrashov Alexander Yu. Rulev 《Magnetic resonance in chemistry : MRC》2010,48(9):661-670
In the series of diaminoenones, large high‐frequency shifts of the 1H NMR of the N? H group in the cis‐position relative to the carbonyl group suggests strong N? H···O intramolecular hydrogen bonding comprising a six‐membered chelate ring. The N? H···O hydrogen bond causes an increase of the 1J(N,H) coupling constant by 2–4 Hz and high‐frequency shift of the 15N signal by 9–10 ppm despite of the lengthening of the relevant N? H bond. These experimental trends are substantiated by gauge‐independent atomic orbital and density functional theory calculations of the shielding and coupling constants in the 3,3‐bis(isopropylamino)‐1‐(aryl)prop‐2‐en‐1‐one (12) for conformations with the Z‐ and E‐orientations of the carbonyl group relative to the N? H group. The effects of the N? H···O hydrogen‐bond on the NMR parameters are analyzed with the atoms‐in‐molecules (AIM) and natural bond orbital (NBO) methods. The AIM method indicates a weakening of the N? H···O hydrogen bond as compared with that of 1,1‐di(pyrrol‐2‐yl)‐2‐formylethene (13) where N? H···O hydrogen bridge establishes a seven‐membered chelate ring, and the corresponding 1J(N,H) coupling constant decreases. The NBO method reveals that the LP(O) →σ*N? H hyperconjugative interaction is weakened on going from the six‐membered chelate ring to the seven‐membered one due to a more bent hydrogen bond in the former case. A dominating effect of the N? H bond rehybridization, owing to an electrostatic term in the hydrogen bonding, seems to provide an increase of the 1J(N,H) value as a consequence of the N? H···O hydrogen bonding in the studied diaminoenones. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
7.
The nitrate anion coordinates to the Sn? CH2? Sn unit of the title phosphonium stannate, [Ph4P]+ [(Ph2ClSn)2CH2 ·NO3]?, to give a six‐membered ring having the penta‐coordinated tin atoms in a trigonal bipyramidal geometry. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
8.
Syntheses and X‐ray structural characterizations of two new Cu(II) complexes Cu(tfbz)2(Htfbz)2(phen) ( 1 ) (Htfbz=2,4,5‐trifluorobenzoic acid, phen=1,10‐phenanthroline) and [Cu(pfbz)2(phen)]2(Hpfbz)2 ( 2 ) (Hpfbz=pentafluorobenzoic acid) are reported. The first complex crystallizes in the monoclinic space group C2/c with the crystal cell parameters a=1.9903(4) nm, b=1.3688(3) nm, c=1.3623(3) nm, β=97.90(3)°, V=3.6762(13) nm3 and Z=4. The second complex crystallizes in the triclinic space group P‐1 with the crystal cell parameters a=1.7965(4) Å, b=1.9236(2) Å, c=2.0916(2) Å, α=110.156(2) °, β=105.040(3) °, γ=98.123(3) °, V=6.3372(17) nm3 and Z=4. The crystallographic analyses revealed that F···H–C hydrogen bonds in both complexes lead to formation of infinite three‐dimensional supramolecular networks. A large number of F···F interactions in complex 2 ensure the stability of intricate crystal structure. 相似文献
9.
Study on the Phase Diagram of CsCl-CeCl3-HCl(11%)-H2O System and the Properties of the Compounds 总被引:2,自引:0,他引:2
The equilibrium solubility of CsCl-CeCl3-HCl(11%)-H2O qua-ternary system at 25℃ has been determined by the physicchemical analysis method ,and the phase diagram was plotted, Two new double salts 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O obtained from the complicated system were identified and characterized by XRD,TG-DTA ,DSC,UV and fluorescence spectroscopy, Studies on the fluorescence excitation and emission show that 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O have upconversion luminescence of infrared-visible range,and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl. 相似文献
10.
Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(S) have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141 ±0.095) K, (18.809±0.088) kJ·mol ^-1 and (51.093±0.239) J·K^-1·mol^-1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X=f(T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K. 相似文献
11.
Liliana Mammino Mwadham M. Kabanda 《International journal of quantum chemistry》2012,112(14):2650-2658
Acylphloroglucinols (ACPLs) are polyphenolic compounds derivative from phloroglucinol, characterized by the presence of at least one COR group and exhibiting a variety of biological activities, which makes them interesting for drug development possibilities. This study investigates patterns in the ways in which weaker intramolecular hydrogen bonds contribute to their conformational stabilization, considering the C? H···O H‐bonds, present in all ACPLs, and the O? H···π H‐bonds, present in ACPLs in which one or more substituents contain a π bond or system sufficiently close to a phenol OH for the H‐bond to be possible. The results in vacuo and in three different solvents (chloroform, acetonitrile, and water) show that, whereas C? H···O plays a significant roles in all these media, the role of O? H···π decreases with increasing solvent polarity. Calculations in vacuo are performed at various levels to enable performance comparisons; calculations in solution use the polarizable continuum model. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
12.
Mohammad Kazem Rofouei Zahra Ghalami Dr. Jafar Attar Gharamaleki Vanik Ghoulipour Giuseppe Bruno Hadi Amiri Rudbari 《无机化学与普通化学杂志》2012,638(5):798-803
The title ligand, [1‐(2‐methoxyphenyl)‐3‐(4‐chlorophenyl)]triazene, H L ( 1 ), was prepared. In a reaction with Hg(NO3)2 it forms the complex [Hg(C26H22Cl2N6O2)], [Hg L 2] ( 2 ). Both compounds were characterized by means of X‐ray crystallography, CHN analysis, FT‐IR, 1H NMR, and 13C NMR spectroscopy. In the structure of compound 1 , two independent fragments are present in the unit cell. They exhibit trans arrangement about the –N=N– double bond. The dihedral angles between two benzene rings in both fragments are 4.36 and 18.79 Å, respectively. Non‐classic C–H ··· N hydrogen bonding and C–H ··· π interactions form a layer structure along the crystallographic ab plane [110]. In compound 2 , the HgII atom is hexacoordinated by two tridentate [1‐(2‐methoxyphenyl)‐3‐(4‐chlorophenyl)]triazenide ligands through a N2O2 set. In addition, in the structure of 2 , monomeric complexes are connected to each other by C–H ··· π stacking interactions, resulting in a 2D architecture. These C–H ··· π edge‐to‐face interactions are present with H ··· π distances of 3.156 and 3.027 Å. The results of studies of the stoichiometry and formation of complex 2 in methanol solution were found to support its solid state stoichiometry. 相似文献
13.
P. R. Seshadri D. Velmurugan J. Govindaraj S. Kannadasan P. C. Srinivasan S. Shanmuga Sundara Raj H.‐K. Fun M. J. Kim 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o700-o703
The title compounds, C20H25N2O2S+·I?, (I), and C29H25BrN2O2S, (II), respectively, both crystallize in space group P. The pyrrole ring subtends an angle with the sulfonyl group of 33.6° in (I) and 21.5° in (II). The phenyl ring of the sulfonyl substituent makes a dihedral angle with the best plane of the indole moiety of 81.6° in (I) and 67.2° in (II). The lengthening or shortening of the C—N bond distances in both compounds is due to the electron‐withdrawing character of the phenylsulfonyl group. The S atoms are in distorted tetrahedral configurations. The molecular structures are stabilized by C—H?O and C—H?I interactions in (I), and by C—H?O and C—H?N interactions in (II). 相似文献
14.
Soumya Basu Basab Chattopadhyay A. Ganguly P. Chakraborty P. Roy Chowdhury S. Samanta M. Mukherjee A. K. Mukherjee S. K. Choudhuri 《应用有机金属化学》2009,23(12):527-534
A mononuclear copper (II) complex of N‐2‐hydroxyhippuric acid (2HHA), [Cu(HA)(H2O)2], has been synthesized and characterized by spectroscopic and X‐ray powder diffraction studies. Crystal structure of [Cu(HA)(H2O)2] reveals a distorted square‐pyramidal geometry around the metal center. The crystal packing in the complex exhibits a three‐dimensional framework formed by intermolecular O? ; H···O and C? H···O hydrogen bonds. Toxicity and antitumor properties of the complex have been studied in vivo. The complex, capable of depleting glutathione (GSH) at nontoxic doses, may be utilized to sensitize drug‐resistant cells where resistance is due to an elevated level of GSH. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
Sabahat
zcan Engin Kendi Meral Tunbilek Hakan Gker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):459-460
The title compound, C21H23ClN4O2·0.5H2O, contains two independent molecules in the asymmetric unit. In each molecule the piperazine ring adopts a chair conformation; the deviations of the piperazine N atoms from the best plane through the remaining four C atoms are ?0.678 (3) and 0.662 (3) Å in molecule A, and 0.687 (3) and ?0.700 (3) Å in molecule B. The molecules are linked by two hydrogen bonds of the O—H?N type involving the O atom of the water molecule of crystallization. 相似文献
16.
Jing‐Yuan Xu He‐Dong Bian Qing‐Lun Wang Wen Gu Shi‐Ping Yan Dai‐Zheng Liao Peng Cheng Zong‐Hui Jiang Pan‐Wen Shen 《无机化学与普通化学杂志》2003,629(6):1063-1067
Two new transition metal(II) complexes [M(hdpa)2(N(CN)2)2] (M = Mn ( 1 ), Co ( 2 ); hdpa = 2, 2'‐dipyridylamine) have been prepared and characterized structurally and magnetically. Both compounds crystallize in the monoclinic space group C2/c. 1 and 2 are isotypic with the unit cell parameters a = 8.634(9), b = 13.541(14), c = 21.99(2) Å, β = 94.806(18)°, and V = 2562(5) Å3 for 1 , a = 8.617(3) Å, b = 13.629(5)Å, c = 21.598(8)Å, β = 94.593(6)°, and V = 2528.4(15)Å3 for 2 , and Z = 4 for both. According to X‐ray crystallographic studies, each metal(II) ion was six‐coordinated with four nitrogen atoms from two bidentate hdpa ligand and two nitrogen atoms from two N(CN)— anions to form slightly distorted octahedrons. Adjacent complex molecules are connected by hydrogen bonds or π···π interactions to form three‐dimensional network. The IR and UV spectroscopy were measured and the magnetic behaviors were investigated. 相似文献
17.
Ming Sun Alasdair C. Macculloch Thomas A. Hamor Richard T. Walker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):116-117
The pyrimidine ring of the title compound, C11H16N2O5S·H2O, is planar to within 0.026 (1) Å and makes an angle of 77.73 (8)° with the mean plane of the thiosugar ring. In terms of standard nucleoside nomenclature, this ring has a C1′‐exo,C2′‐endo conformation. The O5′—C5′—C4′—C3′ torsion angle is ?167.4 (2)° and the glycosidic S4′—C1′—N1—C2 torsion angle is ?101.8 (2)° (anti). 相似文献
18.
Structural and Solution Studies of two Mercury(II) Complexes with [1,3‐Bis(2‐ethoxy)benzene]triazene
Mohammad Kazem Rofouei Jafar Attar Gharamaleki Ehsan Fereyduni Abolfazl Aghaei Giuseppe Bruno Hadi Amiri Rudbari 《无机化学与普通化学杂志》2012,638(1):220-223
The reaction of [1,3‐bis(2‐ethoxy)benzene]triazene, [ HL ], with Hg(SCN)2 and Hg(CH3COO)2, resulted in the formation of the complexes [Hg L (SCN)] ( 1 ) and [Hg L 2] · CH3OH ( 2 ). They were characterized by means of X‐ray crystallography, CHN analysis, FT‐IR, 1H NMR, and 13C NMR spectroscopy. The structure of compound 1 consists of two independent complexes in which the HgII atoms are stacked along the crystallographic a axis to form infinite chains. Each HgII atom is chelated by one L ligand and one SCN ligand, whereas in compound 2 , the HgII atom is surrounded by two L ligands. In addition, 1D chains formed by metal–π interactions are connected to each other by C–H ··· π stacking interactions in the structure of 1 , which results in a 2D architecture. An interesting feature of compound 2 is the presence of C–H ··· π edge‐to‐face interactions. 相似文献
19.
Jacek Zaleski Zdzisaw Daszkiewicz Janusz B. Kyzio 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):754-757
In the title compounds, C6H8N3O2+·NO3? and C5H6N3O2+·CH3SO3?, respectively, the cations are almost planar; the twist of the nitramino group about the C—N and N—N bonds does not exceed 10°. The deviations from coplanarity are accounted for by intermolecular N—H?O interactions. The coplanarity of the NHNO2 group and the phenyl ring leads to the deformation of the nitramino group. The C—N—N angle and one C—C—N angle at the junction of the phenyl ring and the nitramino group are increased from 120° by ca 6°, whereas the other junction C—C—N angle is decreased by ca 5°. Within the nitro group, the O—N—O angle is increased by ca 5° and one O—N—N angle is decreased by ca 5°, whereas the other O—N—N angle remains almost unchanged. The cations are connected to the anions by relatively strong N—H?O hydrogen bonds [shortest H?O separations 1.77 (2)–1.81 (3) Å] and much weaker C—H?O hydrogen bonds [H?O separations 2.30 (2)–2.63 (3) Å]. 相似文献
20.
(Zn1-xMnx)C2O4·2H2O在空气中的热分解动力学研究 总被引:1,自引:0,他引:1
用热分析(TG-DTG/DTA)、X射线衍射(XRD)技术和透射电镜(TEM)研究了固态物质Zn1-xMnxC2O4•2H2O在空气中热分解的过程。热分析结果表明,Zn1-xMnxC2O4•2H2O在空气中分两步分解,其失重率与理论计算失重率相吻合。 XRD和TEM结果表明,Zn1-xMnxC2O4•2H2O分解的最终产物为Zn1-xMnxO,其颗粒大小约为10-13
nm。在非等温条件下对Zn1-xMnxC2O4•2H2O的热分解动力学进行了分析。用Friedman法和Flynn-Wall-Ozawa(FWO)法求取了分解过程的活化能E,并用多元线性回归给出了可能的机理函数。Zn1-xMnxC2O4•2H2O两步热分解的活化能分别为155.7513 kJ/mol 和215.9397 kJ/mol。 相似文献