2-乙酰吡嗪苯甲酰腙钴、锌和铜配合物的晶体结构及荧光性质

合成了配合物[Co(L)_2](1),[Zn(L)_2](2)和[Cu_2(L)_2Cl_2](3)(HL为2-乙酰吡嗪苯甲酰腙),并通过单晶衍射、元素分析及红外光谱表征了它们的结构。单晶衍射结果表明,配合物1和2同构,配体和金属的比例为2∶1。每个配合物中,中心金属离子与来自2个阴离子配体L-的N_2O电子供体配位,形成扭曲的八面体配位构型。在双核配合物3中,Cu(Ⅱ)离子与1个阴离子三齿酰腙配体、2个μ2桥联的氯离子配位,拥有扭曲的四方锥配位构型。此外还研究了配合物的荧光性质。     

喹啉酰腙铜锌配合物的结构及荧光性质（英文）

合成了配合物{[Cu(L)(OAc)]·Me OH}n(1)和[Zn(L)(OAc)]n(2)(HL为喹啉-8-甲醛缩异烟肼),并通过单晶X射线衍射、元素分析、红外光谱表征了结构。单晶衍射结果表明,除了结晶溶剂不同,2个配合物结构类似。每个配合物中,中心金属离子与来自烯醇化脱质子配体L-的2个O原子和1个N原子,1个单齿配位的醋酸根和相邻配体4-吡啶N原子配位,形成一维链状结构。但配合物中金属离子的配位构型分别为扭曲的四方锥和三角双锥。在360 nm紫外光激发下,甲醇溶液中配合物2在510 nm左右有很强的荧光发射,这是由锌离子配位荧光增强效应所导致。     

五配位四方锥混合配体配合物…

近年来 ,由于混合配体配合物在生物过程、催化、磁化学、分析化学等方面的重要作用 ,对这类配合物的研究越来越受到重视[1 ,2 ] 。五配位四方锥Cu(Ⅱ )配合物在立体化学、光化学和生物化学上都有重要意义 ,因而受到了广泛的关注[3,4] 。对于具有 5个等同配位原子的五配位d9离子Cu(Ⅱ ) ,通常有拉长四方锥 (SP)或压扁的三角双锥 (TBP) 2种稳定配位构型 ,后者的能量较低 ,更稳定。当配体具有立体张力的刚性时 ,四方锥构型往往得到稳定化。由于草胺酸、草酰胺具有多样性配位方式 ,带取代基的草胺酸、草酰胺配位的单核配合物断片是分子基材料…     

含吡嗪的缩氨基脲配体Ni(Ⅱ)/Cd(Ⅱ)配合物的晶体结构及与DNA的相互作用（英文）

合成配合物[NiL_2]·CH_3OH·0.5H_2O(1)和[Cd(HL)Cl_2](2)(HL=3-甲基2-乙酰吡嗪缩4-苯基氨基脲)并通过单晶衍射、元素分析及红外光谱表征其结构。单晶衍射结果表明,配合物1中,Ni(Ⅱ)离子与2个拥有N_2O电子供体的阴离子配体L-配位,配位构型为扭曲的八面体。而配合物2中,Cd(Ⅱ)离子与1个中性三齿配体HL和2个氯离子配位,拥有扭曲的四方锥配位构型。荧光光谱结果表明,配合物与DNA的相互作用强于配体。     

3-乙基-2-乙酰吡嗪缩4-苯基氨基脲Ag(Ⅰ)配合物的合成、结构和DNA结合性质（英文）

合成并通过单晶衍射、元素分析及红外光谱表征了配合物[Ag_2(HL)(NO_3)_2]_n(1)的结构(HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲)。单晶衍射结果表明,配合物1中,HL作为中性四齿配体连接2个Ag(Ⅰ)中心,其中一个Ag(Ⅰ)中心与HL配体中的ON_2供体(羰基O,亚胺N和吡嗪N1原子)和2个单齿硝酸根配位,构成扭曲的四方锥配位构型;而另一个Ag(Ⅰ)离子与1个单齿硝酸根,1个双齿硝酸根和HL配体中的吡嗪N_4原子配位,形成扭曲平面正方形配位构型。另外,相邻的Ag(Ⅰ)离子通过桥联的硝酸根离子相互连接形成二维层状结构;此外,配合物1与DNA的相互作用强于配体。     

三个包含酰胺型配体铜/锌配合物的合成、结构及荧光性质（英文）

合成并通过单晶衍射表征了3个配合物[Cu LCl2]·CH3CN(1),[Cu LBr2]·CH3CN(2)和[Zn L(NO3)2]·CH3CN(3)(L=2-(5-氯-8-喹啉氧基)-1-(吡咯烷-1-基)乙酮)。在配合物1和2中,五配位的铜离子采取扭曲的四方锥配位构型,与来自配体L的2个氧原子和1个氮原子及2个卤离子配位。而在配合物3中,锌离子与1个三齿配位的配体L,1个单齿配位的硝酸根和1个双齿配位的硝酸根配位,配位构型为扭曲的八面体。乙腈溶液中,配合物1和2在410 nm处的最大荧光发射峰与配体L的相似,强度有所降低。而配合物3由于配体到锌离子之间的能量转移,最大荧光发射峰红移至430 nm。     

酰胺型配体铜、锌、银配合物的合成、结构及荧光性质（英文）

合成并通过单晶衍射表征了5个配合物[Cu LCl2]·CH3COCH3(1)、[Zn LCl2]·CH3COCH3(2)、[Zn L(NO3)2]·0.5CH3COCH3(3)、[Ag L2]Cl O4(4)和[Ag L2]BF4(5)(L=2-(5-氯-8-喹啉氧基)-1-(吡咯烷-1-基)乙酮)。配合物1和2同构,五配位的中心金属离子采取扭曲的四方锥配位构型,与来自配体L的2个氧原子和1个氮原子及2个氯离子配位。而在配合物3中,锌离子与1个三齿配位的配体L,1个单齿配位的硝酸根和1个双齿配位的硝酸根配位,配位构型为扭曲的八面体。配合物4和5中,中心金属与配体的比例为1∶2。银离子与2个三齿配位的配体L配位,采取扭曲的八面体配位构型。乙腈溶液中,配合物1、2、4和5在410 nm处的最大荧光发射峰与配体L相似。而配合物3由于配体到锌离子之间的能量转移,最大荧光发射峰红移至430 nm。     

3-乙基-2-乙酰吡嗪缩4-苯基氨基脲铜/锌配合物的晶体结构及荧光性质（英文）

合成了配合物[Cu(HL)(H_2O)(NO3)]NO3(1)和[Zn(HL)Cl2](2)(HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲),并通过单晶X射线衍射、元素分析及红外光谱表征了结构。单晶衍射结果表明,配合物1中,中心Cu(Ⅱ)离子与1个中性三齿缩氨基脲配体,1个水分子和1个硝酸根配位,配位构型为扭曲的四方锥。配合物2中Zn(Ⅱ)离子周围的配位原子为N2OCl2,其配位构型与配合物1中Cu(Ⅱ)离子的相同。甲醇溶液中,配合物2的荧光发射峰与配体HL相似。而配合物1由于配体和金属离子之间的能量转移,最大荧光发射峰略有红移。     

基于非对称salamo型N_2O_4配体的四核镍和锌配合物的合成、晶体结构、Hirshfeld表面分析与荧光性质（英文）

设计并合成了2种新型的salamo型N_2O_4配体的四核过渡金属配合物:[Ni_2(L)(μ-OAc)(CH_3OH)]_2·4CH_3OH (1)和[Zn_2(L)(μ-OAc)(CH_3CH_2OH)]2(2)(H_3L=6-hydroxy-6′-methoxy-2,2′-(ethylenediyldioxybis(nitrilomethylidyne))diphenol),并用元素分析、红外光谱、紫外-可见光谱、荧光光谱、Hirshfeld表面分析和单晶X射线晶体学对配合物进行了表征。X射线晶体学分析表明,配合物1和2均为对称的四核配合物。配合物1中所有六配位的镍原子都形成了扭曲的八面体几何构型,而配合物2中的所有五配位的锌原子则形成了扭曲的四方锥和三角双锥几何构型。     

金属-血清白蛋白的结构研究II. Cu(II)-BSA和Ni(II)-BSA的四 方锥-四方平面 结构

本文用紫外光谱研究Cu(II)-BSA和Ni(II)-BSA配合物的结构随BSA浓度的变化,发现当浓度增大并>2×10^-^4～3×10^-^4mol.dm^-^3时,这两种配合物从五配位的四方锥构型转变成四配位的四方平面构型,首次提供了BSA的Asp羧基氧参与同Cu(II)和Ni(II)配位的证据。计算并讨论了Cu(II),Ni(II)和有关配体轨道的光学电负性。     

Preparation and characterisation of copper,cobalt and nickel complexes of tetradentate N6 macrocyclic ligand

Macrocyclic complexes of copper, nickel and cobalt were synthesised via template reactions. These 14-membered N₆ tetradentate macrocyclic complexes were characterised by magnetic, conductance, electronic and IR spectral studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by 2,3-butanedione, moieties, but far IR spectra suggest that the pyridine nitrogens are not coordinated. These macrocyclic complexes are considered to have distorted octahedral configurations.     

Self‐assembly properties of Salamo‐type trinuclear Cu(II) and Co(II) complexes based on the regulation of H+/OHˉ

A novel naphthalenediol‐based bis(salamo)‐type tetraoxime compound (H₄L) was designed and synthesized. Two new supramolecular complexes, [Cu₃(L)(μ‐OAc)₂] and [Co₃(L)(μ‐OAc)₂(MeOH)₂]·4CHCl₃ were synthesized by the reaction of H₄L with Cu(II) acetate dihydrate and Co(II) acetate dihydrate, respectively, and were characterized by elemental analyses and X‐ray crystallography. In the Cu(II) complex, Cu1 and Cu2 atoms located in the N₂O₂ sites, and are both penta‐coordinated, and Cu3 atom is also penta‐coordinated by five oxygen atoms. All the three Cu(II) atoms have geometries of slightly distorted tetragonal pyramid. In the Co(II) complex, Co1 and Co3 atoms located in the N₂O₂ sites, and are both penta‐coordinated with geometries of slightly distorted triangular bipyramid and distorted tetragonal pyramid, respectively, while Co2 atom is hexa‐coordinated by six oxygen atoms with a geometry of slightly distorted octahedron. These self‐assembling complexes form different dimensional supramolecular structures through inter‐ and intra‐molecular hydrogen bonds. The coordination bond cleavages of the two complexes have occurred upon the addition of the H⁺, and have reformed again via the neutralization effect of the OH^?. The changes of the two complexes response to the H⁺/OH^? have observed in the UV–Vis and ¹H NMR spectra.     

Crystal structure of (1,10-phenanthroline-N,N')(1,4,7,10-tetraazacyclododecane-N,N',N",N"')nickel(II) diperchlorate.

The crystal structure of the title compound, [Ni(C8H20N4)(C12H8N2)](ClO4)2, has been determined by X-ray diffraction. The Ni(II) ion is six coordinated with four nitrogen atoms of the tetradentate macrocyclic ligand and two nitrogen atoms of the bidentate ligand in a distorted octahedron geometry. The folded tetradentate macrocyclic ligand adopts a configuration having four five-membered chelate rings in distorted eclipsed conformations. The four hydrogen atoms of the amine groups of the macrocyclic ligand are on the same side towards the bidentate ligand.     

Infrared spectra and electronic structures of agostic uranium methylidene molecules

Through reactions of laser-ablated uranium atoms with methylene halides CH2XY (XY = F2, FCl, and Cl2), a series of new actinide methylidene molecules CH2UF2, CH2UFCl, and CH2UCl2 are formed as the major products. The identification of these complexes has been accomplished via matrix infrared spectra, isotopic substitution, and relativistic density functional calculations of the vibrational frequencies and infrared intensities. Density functional calculations using the generalized gradient approach (PW91) show that these CH2UXY methylidene complexes prefer highly distorted agostic structures rather than the ethylene-like symmetric structures. The calculated agostic angles ([angle]H-C-U) are around 89 degrees for all the three uranium complexes, and the predicted vibrational modes and isotopic shifts agree well with experimental values. Electronic structure calculations reveal that these U(IV) molecules all have strong C=U double bonds in the triplet ground states with 5f (2) configurations. The calculated bond lengths and bond energies indicate that the C=U double bonds are slightly weaker in the fluoride species than in the chloride species because of the radial contraction of the U (6d) orbitals by the inductive effect of the fluorine substituent. The agostic uranium methylidene complexes are compared with analogous transition metal and thorium complexes, which reveal interesting differences in their chemistries.     

Synthesis,crystal structure and silver complexation of a novel saddle-shaped stilbenophane: NMR and theoretical study on the complex

A new Z,Z-stilbenophane was synthesised and characterised. According to an X-ray structure analysis, the structure has a saddle shape, with the π-electrons of the double bonds and the oxygen atoms pointing towards the centre of a cavity. The ligand forms a 1:1 complex with Ag⁺. Both NMR spectra and theoretical analysis (Gauge-independent atomic orbitals (GIAO) and Quantum theory of atoms in molecules (QTAIM)) suggest that the silver cation is bound within the molecular cavity. The metal is coordinated by the two olefinic double bonds and the four oxygen atoms in an approximately octahedral environment. The coordination motif is unusual because the soft silver cation prefers the interaction with the four hard oxygen atoms over the bonding to the arene units, which is frequently observed in Ag⁺ arene complexes.     

Copper(II) complexes containing hemilabile tridentate ligand as chromotropic probes

Two copper(II) complexes with the general formula [Cu(L)(H₂O)](ClO₄)₂ (1) and [Cu(L)₂](ClO₄)₂ (2), where L=3-((pyridin-2-ylmethyl)amino)propanamide, were synthesized and characterized by elemental analyses, IR, UV–vis spectroscopy techniques and molar conductance measurements. The crystal structures of the complexes were identified by single crystal X-ray diffraction analysis. The tridentate ligand L acts as an N₂O-donor through the nitrogen atoms of the pyridine and amine moieties as well the oxygen atom of the amide group. The copper(II) ions in both complexes have distorted octahedron structures so that the Cu(II) ion in 1 is coordinated by an aqua ligand and a tridentate ligand defining the basal plane, and by two oxygen atoms of the perchlorate ions occupying the axial positions. However, two ligands L are coordinated to the copper(II) ion in 2, where four nitrogen atoms of pyridine and amine groups occupy the equatorial positions and two oxygen atoms of the amide moieties exist in the apices. The chromotropism (halo-, solvato- and ionochromism) of both complexes were studied using visible absorption spectroscopy. The complexes are soluble in water and organic solvents and display reversible halochromism. The solvatochromism property is due to structural change followed by solvation of the vacant sites of the complexes. The complexes demonstrated obvious ionochromism and are highly sensitive and selective towards CN^? and N₃^? anions in the presence of other halide and pseudo-halide ions.     

Electronic structure,chemical bonding,and oxidation numbers of first‐row transition metals in [MePIm2] complexes and their cations

The qualitative structures of the upper one‐electron energy levels of imidazole‐coordinated first‐row transition metal porphyrin [MePIm₂] complexes established in the present study have shown that the second oxidation number of the first‐row transition metals in the neutral complexes do not change in their cations and double cations. It was found that occupied orbitals of the density functional theory method obtained with B3LYP functional are not correctly ordered. Therefore, they cannot be used in investigations of the orbital structure of the upper molecular orbitals. A qualitative analysis of density functional theory method wave functions in terms of Mulliken and natural charges of atoms, together with an analysis of electrostatic potentials of the neutral [MePIm₂] complex, its single and double cations, demonstrates that the highest occupied orbitals of these complexes are mainly formed by atomic orbitals of the porphyrin ring atoms. Therefore, transition metal atoms are not active in chemical reactions with these complexes unless the 3d electrons of transition metal atoms are excited, for example by light. A mechanism of an electron transfer reaction that occurs between a heme cytochrome and Fe‐oxide mineral surface is discussed in the light of the obtained results. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Complexes of gadolinium and erbium iodides with carbamide: Synthesis and structures

The novel carbamide complexes of gadolinium and erbium iodides of the composition LnI₃4Ur·4H₂O (Ln = Gd, Er; Ur = carbamide) were synthesized and studied by X-ray diffraction and IR spectroscopy. The ligands are coordinated to the central Gd or Er atom through the O atoms of water or carbamide molecules. The coordination polylhedron of Ln atoms is a distorted square antiprism. The iodide ions are not coordinated and lie in the outer sphere.     

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}的晶体和分子结构

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}单晶样品在Nicolet-R3四圆衍射仪上收集X射线衍射数据. 分析结果给出其晶胞参数: a=22.125(6), b=11.313(3),c=25.053A; β=118.05(2)°; V=5534.19A^3, Z=4, 空间群Cc. 衍射数据经过Lρ因子和经验吸收效应校正. 分子中铁原子的位置从三维Patterson图上得到. 接着经过若干轮Fourier和差Fourier电子云密度合成, 发现全部其余非氢原子的坐标.氢原子位置根据理论模型计算. 结构修正最后收敛至R=0.073, Rw=0.069. 标题化合物是由[(C2H5)4N]^+和{FeS4[S2CN(C2H5)2]}^2^-组成的离子型化合物. 结构的主要特点表现在阴离子上, 而在阴离子中含有类立方烷型簇核Fe4S4. 该簇核中每个铁原子与五个硫原子配位, 其配位多面体构型均为畸变的四方锥.     

Structure and dynamics of binary and ternary lanthanide(III) and actinide(III) tris[4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione] (TTA)-tributylphosphate (TBP) complexes. Part 3, the structure, thermodynamics and reaction mechanisms of 8- and 9-coordinated binary and ternary Y-TTA-TBP complexes studied by quantum chemical methods

Possible mechanisms for intermolecular exchange between coordinated and solvent water in the complexes Y(TTA)(3)(OH(2))(2) and Y(TTA)(3)(TBP)(OH(2)) and intermolecular exchange between free and coordinated HTTA in Y(TTA)(3)(OH(2))(HTTA) and Y(TTA)(3)(TBP)(HTTA) have been investigated using ab initio quantum chemical methods. The calculations comprise both structures and energies of isomers, intermediates and transition states. Based on these data and experimental NMR data (Part 2) we have suggested intimate reaction mechanisms for water exchange, intramolecular exchange between structure isomers and intermolecular exchange between free HTTA and coordinated TTA. A large number of isomers are possible for the complexes investigated, but only some of them have been investigated, in all of them the most stable geometry is a more or less distorted square anti-prism or bicapped trigonal prism; the energy differences between the various isomers are in general small, less than 10 kJ mol(-1). 9-coordinated intermediates play an important role in all reactions. Y(TTA)(3)(OH(2))(3) has three non-equivalent water ligands that can participate in ligand exchange reactions. The fastest of these exchanging sites has a QM activation energy of 18.1 kJ mol(-1), in good agreement with the experimental activation enthalpy of 19.6 kJ mol(-1). The mechanism for the intramolecular exchange between structure isomers in Y(TTA)(3)(OH(2))(2) involves the opening of a TTA-ring as the rate determining step as suggested by the good agreement between the QM activation energy and the experimental activation enthalpy 47.8 and 58.3 J mol(-1), respectively. The mechanism for the intermolecular exchange between free and coordinated HTTA in Y(TTA)(3)(HTTA) and Y(TTA)(3)(TBP)(HTTA) involves the opening of the intramolecular hydrogen bond in coordinated HTTA followed by proton transfer to coordinated TTA. This mechanism is supported by the good agreement between experimental activation enthalpies (within parenthesis) and calculated activation energies 68.7 (71.8) and 35.3 (38.8) kJ mol(-1). The main reason for the difference between the two systems is the much lower energy required to open the intramolecular hydrogen bond in the latter. The accuracy of the QM methods and chemical models used is discussed.