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1.
《Journal of Coordination Chemistry》2012,65(22):3748-3762
AbstractA new asymmetric tetradentate Schiff base, bis(5-methoxysalicylidene)-4-methylbenzene-1,2-diamine), H2L, and its Ni(II) complex were prepared and characterized using elemental analyses (CHN), FTIR, UV–Vis, 1H NMR, and 13C{1H} NMR spectroscopic techniques, and crystal structures of both were determined by X-ray crystallography. For both ligand and Ni(II) complex, density functional theory calculations to find geometry parameters, IR frequencies, electronic properties, and natural bond orbital analysis (NBO) were done with M062X method and Def2-TZVP basis set. All calculated data are consistent with the experiments. NBO data for the Ni(II) complex show that the main type of transition in UV-Vis is interligand charge-transfer, which is assigned as π-π*. 相似文献
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Vasudevan Subramaniyan Ashok Kumar Anbarasu Govindaraj Ganesan Mani 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(6):734-739
The reaction of NiCl2 with 1,3‐bis[(diphenylphosphanyl)methyl]hexahydropyrimidine in the presence of 2,6‐dimethylphenyl isocyanide and KPF6 afforded a new pentacoordinated PCP pincer NiII complex, namely {1,3‐bis[(diphenylphosphanyl)methyl]hexahydropyrimidin‐2‐yl‐κN2}(2,6‐dimethylphenyl isocyanide‐κC)nickel(II) hexafluoridophosphate 0.70‐hydrate, [Ni(C9H9N)(C30H30ClN2P2)]PF6·0.7H2O or [NiCl{C(NCH2PPh2)2(CH2)3‐κ3P,C,P′}(Xylyl‐NC)]PF6·0.7H2O, in very good yield. Its X‐ray structure showed a distorted square‐pyramidal geometry and the compound does not undergo dissociation in solution, as shown by variable‐temperature NMR and UV–Vis studies. Density functional theory (DFT) calculations provided an insight into the bonding; the nickel dsp2‐hybridized orbitals form the basal plane and the nearly pure p orbital forms the axial bond. This is consistent with the NBO (natural bond orbital) analysis of analogous nickel(II) complexes. 相似文献
3.
《Polyhedron》1999,18(8-9):1159-1162
The phosphinophosphido niobocene complex Cp2Nb(PHPh2)(PPh2) (2) was prepared by deprotonation of the cationic diphosphino complex [Cp2Nb(PHPh2)2]Cl (3). Complex 2 is thermally unstable and readily dissociates phosphine to give the ortho-metallated complex Cp2Nb(PHPhC6H4−). Crystal structure determination of 2 supported its formulation as the phosphinophosphido compound. The Nb–P(1) (phosphino) bond length is 2.524(2) Å and Nb–P(2) (phosphido) bond length is 2.610(2) Å. 相似文献
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Rüdiger W. Seidel Christina Dietz Jürgen Breidung Richard Goddard Iris M. Oppel 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1112-1115
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
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1 INTRODUCTION During the last decade the manganese che- mistry has aroused great interest due to its diverse redox functions of enzymes in photosystem Ⅱ and its specially structural, magnetic and spectroscopic properties[1, 2]. A lot of manganese complexes involving carboxylate ligands have been reported, and their properties been fully explored[3, 4]. The coordination environment of the manganese site in biosystem often consists of oxygen and nitrogen atoms from the carboxylate groups… 相似文献
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Crystal structures and thermodynamic investigations of NaSc(BH4)4 from first‐principles calculations
Ki Chul Kim 《International journal of quantum chemistry》2013,113(2):119-124
The double cation borohydride NaSc(BH4)4 has a total H2 content of 12.67 wt.% and has been suggested as a potential candidate for hydrogen storage applications. This study reports first‐principles calculations of the structure and reaction thermodynamics of NaSc(BH4)4. The calculations indicate that NaSc(BH4)4 is decomposed into a mixture of ScB2, NaBH4, and Na2(B10H10) with H2 release of 9.3 wt.% at 118 K at a partial pressure of H2 of 100 bar. Reactant compositions that can destabilize NaSc(BH4)4 were evaluated. This effort identified four destabilization reactions that are predicted to have reaction thermodynamics for hydrogen release within the temperature range of 78–109 K. Even though the reactions conclusively produce undesired compounds, such as refractory materials or kinetically stable B12H12‐containing species, the thermodynamic study suggests a direction for improving the thermodynamics of double cation borohydride‐based systems being actively considered for hydrogen storage applications. © 2012 Wiley Periodicals, Inc. 相似文献
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1 INTRODUCTION Recently, the discoveries of antitumor effects ofinorganic complexes, especially of metal complexes,and their applications for curing cancer diseaseshave received increasing attention[1]. As a ligandwith potential S and N donors, thiosem… 相似文献
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Hu Mao-Lin Huang Zhen-Yan Cheng Ya-Qian Wang Shm Lin Juan-Juan Hu Yi Xu Duan-Jun Xu Yuan-Zhi 《中国化学》1999,17(6):637-643
The title complex Eu(III)(TTA)3(phen) (where TTA = thenoyltrifluoroacetone monoanion; phen = 1,10-phenanthroline) has been synthesized in mixed solvents of acetone and ethanol (1:1 volume ratio) and its crystal structure has been determined by X-ray diffraction. The complex crystals are triclinic, space group P 1 (# 2) with cell dimensions of a = 1.32.41 (2) nm, b = 1.5278(4) nm, c = 0.9755(3) nm, α = 92.49 (2)°, β = 102.57(2)°, γ = 91.62(2)°, V = 1.9268(8) nm3, Z = 2, μ (Mo Ka)= 18.77 cm?1, Dx=1.720 g/cm3. The coordination geometry of Eu atom is a distorted square antiprism, and the encapsulated structure that can meet the structural requirement of the typical europium luminescent sensor. The fluorescence spectrum suggests that the complex is a strong photoluminescent material. 相似文献
11.
B. V. Bukvetskii A. G. Mirochnik P. A. Zhikhareva V. E. Karasev 《Journal of Structural Chemistry》2006,47(3):575-580
The crystal structure of [Eu(TTA)2(NO3)(TPPO)2] (I) (TTA = thenoyltrifluoroacetone, TPPO = triphenylphosphine oxide) possessing intense triboluminescence was established by X-ray crystallography. The crystals are triclinic, noncentrocymmetrical: a = 11.047(3) Å, b = 11.794(3) Å, c = 12.537(3) Å; α = 102.635 (4)°, β = 102.088(4)°,γ = 117.765(3)°; space group P1, Z = 1. The central Eu(III) atom coordinates two oxygen atoms of two TPPO molecules at distances of 2.271 Å and 2.282 Å, two oxygen atoms of the nitrate group at distances of 2.478 Å and 2.481 Å, four oxygen atoms of two TTA ions at distances of 2.365 Å, 2.381 Å, and 2.363 Å, 2.371 Å (coordination number is 8). The coordination polyhedron of the Eu(III) atom is a distorted dodecahedron. Possible reasons for spectral differences in the Stark structure of photo-and triboluminescence of I are discussed. 相似文献
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CpRu(PPh3)2SSiiPr3与SCNR(R=Ph,1-Naphthyl)反应的结构、成键与机理的理论研究 总被引:1,自引:0,他引:1
应用密度泛函理论(DFT), 通过CpRu(PH3)2SSiiPr3 (Cp=环戊二烯负离子; iPr=异丙基)与SCNH模型化反应, 探讨了CpRu(PPh3)2SSiiPr3 与SCNR (R=苯基, 萘基)的反应机理, 分析了反应所涉及的各相关化合物的结构与成键特征. 反应中首先失去一个膦配体, 生成一个中间体. 该中间体中, 硫原子采取sp2杂化, 硫原子剩余的一个p轨道与金属中心上的d轨道具有相同的对称性, 因而该p轨道上的孤电子对可与金属中心上的d轨道形成π键, 导致Cp环中心, Ru, S1, P和Si原子在同一平面内, 而不是S1, P和Si原子偏离该平面. 计算结果预测, S=C双键中的p键打开, 生成含金属中心的四元环螯合物一步为反应的决速步骤. 空间位阻的减小、p共轭体系的生成以及螯合环的存在, 是导致该反应热力学有利的重要原因. 相似文献
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[ReCl3(MeCN)(PPh3)2] reacts with bis(3,5-dimethypyrazol-1-yl)methane (bdmpzm) in acetone to give [ReCl3(bdmpzm)(PPh3)]. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The molecular orbital diagram of [ReCl3(bdmpzm)(PPh3)] has been calculated with the density functional theory (DFT) method. 相似文献
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The crystal structure of the title compound UO2(NO3)2[CH2(CH2)2CONC8H17] was determined by single-crystal X-ray diffraction. Crystal data: triclinic, space group P ī, a = 7.456(2), b = 8.371(2), c = 13.470(3)A, α = 95.66(1), β = 94.64(2), γ = 102.67(2)°, C24H46N4O10U, Mr = 788.68, V = 811.73A3, Dc = 1.613 g/cm3, Z = 1, F(000) = 390, μ = 5.052 mm-1, the final R = 0.0256 and wR = 0.0568 for 2826 observed reflections I>2σ(I). The central uranyl ions are coordinated by six oxygen atoms. Two of them are from the carbonyl groups of N-octyl--pyrrolidone molecules, and the other four from two nitrate groups. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(8):1413-1428
The reaction of 1?:?4.4?M proportion of cis-[ReO2I(PPh3)2] and 4-aminopyridine (ampy) in acetone–water gives trans-[ReO2(ampy)4]I·2H2O (1a) in 85% yield. 1a has been characterized by C, H, and N microanalyses, FT-IR, UV–vis, 1H NMR spectroscopy, and molar conductivity. The X-ray crystal structure of 1a reveals an octahedral trans dioxorhenium(V) complex with a “N4O2” coordination for rhenium. 1a has an orthorhombic space group C2221 with a?=?17.576(4), b?=?19.370(4), c?=?15.730(4) Å, V?=?5355(2) Å3, and Z?=?8. Geometry optimization of the trans-O,O complex, 1a and its cis-O,O analog, 1b performed at the level of density functional theory reveal that 1a is more stable than 1b by 25?kcal M–1 in the gas phase. The electronic spectrum of 1a was also analyzed at the level of time-dependent density functional theory. Excitation of 1a in methanol at 450?nm leads to a fluorescent emission at 505?nm with a quantum yield (Ф) of 0.04. Electrochemical studies of 1a in acetonitrile show a quasi-reversible Re(V) to Re(VI) oxidation at 0.618?V versus Ag/AgCl. This redox potential matches with the calculated redox potential of 0.621?V versus Ag/AgCl. 相似文献
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Kovalevsky AY King G Bagley KA Coppens P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(24):7254-7264
Photocrystallographic experiments show that laser exposure of crystals of [Ru(bpy)2(NO)(NO2)](PF6)2 at 90 K produces a double isonitrosyl-nitrito linkage isomer and provide the detailed geometry of the metastable species generated. The analysis indicates that the isomerization is accomplished through an intramolecular redox reaction involving oxygen transfer from the nitro to the nitrosyl group. At 200 K only a single (nitrito) linkage isomer is formed with a U-shaped conformation of the nitrito group rather than the Z conformation observed at 90 K. A mechanism for the isomerization is proposed based on the crystallographic results and FTIR data collected at low temperatures during the isomerization process. The study presents the first structural evidence for double linkage isomerization in transition-metal complexes. 相似文献
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The reaction of copper dichloride dihydrate and bis(3,5-dimethylpyrazol-1-yl)methane affords [Cu{H2C(3,5-Me2pz)2}2Cl]Cl · 3H2O. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of the [Cu{H2C(3,5-Me2pz)2}2Cl]+ cation has been calculated with the density functional theory (DFT) method. The spin-allowed doublet–doublet electronic transitions of [Cu{H2C(3,5-Me2pz)2}2Cl]+ have been calculated with the time-dependent DFT method, and the UV–Vis spectrum of the title compound has been discussed on this basis. 相似文献
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The reaction of copper(II) nitrate trihydrate and 2-(2-pyridyl)benzimidazole (pybzim) leads to [Cu(pybzim)2(NO3)](NO3). The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of the [Cu(pybzim)2(NO3)]+ cation has been calculated with the density functional theory (DFT) method. The spin-allowed doublet–doublet electronic transitions of [Cu(pybzim)2(NO3)]+ have been calculated with the time-dependent DFT method, and the UV–Vis spectrum of the title compound has been discussed on this basis. 相似文献
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1INTRODUCTIONHomo dinuclearmetalcarbonylclustershavebenstudiedwidelyfortheirnovelstructuresandusesinorganicsynthesis〔1〕.Examp... 相似文献
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PENG Yan-Fena② LIU Tian-Baoa YANG Xiao-Honga LI Bao-Longb a 《结构化学》2006,25(7):793-796
1 INTRODUCTION Crystal engineering principles have been employ- yed in recent years to produce a variety of coordi- nation networks[1], which are of great current interest not only for their potential properties as functional solid materials[2] in host-guest chemistry, ion ex- change and catalysis, but also for their often com- plicated intriguing architectures and topologies. Ra- tional control the construction of polymeric net- works remains a great challenge in crystal engineer- ing. Mu… 相似文献