Hydrothermal Synthesis,Crystal Structure,Spectrum Properties and Quantum Chemical Calculation of a Trinuclear Copper（Ⅱ） Complex with 3-（Pyridin-2-yl）-1,2,4-triazole

A three-dimensional framework copper(Ⅱ) coordination polymer with copper carbonate basic and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) has been hydrothemally synthesized.The complex (2,C14 H10 CuN8 ·3H2 O) crystallizes in tetragonal,space group P4 2 /n,a=2.08581(12),b=2.08581(12),c=0.72331(4) nm,M r=761.73,V=3.1468(3) nm 3,Dc=1.608 g/cm 3,Z=4,F(000)=1552,GOOF=1.07,R=0.0515 and wR=0.1689.Every asymmetric unit molecular structure of the complex is composed with one copper ion,one and half water molecules and two Hpt molecules.Each copper ion is coordinated with five nitrogen atoms from four Hpt molecules,forming a distorted square pyramidal geometry.The fluorescence spectrum analysis shows that the title complex at room temperature exhibits intense photoluminescence with maximum emission at 450 nm.The quantum chemistry calculation study on the complex has been performed.The stability,some frontier molecular orbital energies and composition characteristics of some frontier molecular orbitals of the complex have been investigated.     

Syntheses,structures and catecholase activities of homo‐ and hetero‐trinuclear cobalt(II) complexes constructed from an acyclic naphthalenediol‐based bis(Salamo)‐type ligand

A series of homo‐ and hetero‐trinuclear cobalt(II) complexes [Co₃(L)(OAc)₂(CH₃CH₂OH)(H₂O)] ( 1 ), [Co₂Ba(L)(OAc)₂] ( 2 ) and [Co₂Ca(L)(OAc)₂]·CHCl₃ ( 3 ), containing an acyclic naphthalenediol‐based ligand H₄L were synthesized. All the three complexes were characterized by elemental analyses, IR, UV – vis spectra and single crystal X‐ray diffraction analyses. Comparative studies of the structures and spectroscopic properties are carried out on these complexes. All of the complexes show catechol oxidase activities in MeCN. Using UV – vis spectroscopy, we monitored the aerial oxidation of 3,5‐di‐tert ‐butylcatechol (3,5‐DTBCH₂) to 3,5‐di‐tert ‐butylquinone (3,5‐DTBQ), which confirms the essential role of these complexes in enhancing the catalytic reaction.     

X‐Ray Diffraction and Mössbauer Spectroscopy Studies of Pressure‐Induced Phase Transitions in a Mixed‐Valence Trinuclear Iron Complex

The mixed‐valence complex Fe₃O(cyanoacetate)₆(H₂O)₃ ( 1 ) has been studied by single‐crystal X‐ray diffraction analysis at pressures up to 5.3(1) GPa and by (synchrotron) Mössbauer spectroscopy at pressures up to 8(1) GPa. Crystal structure refinements were possible up to 4.0(1) GPa. In this pressure range, 1 undergoes two pressure‐induced phase transitions. The first phase transition at around 3 GPa is isosymmetric and involves a 60° rotation of 50 % of the cyanoacetate ligands. The second phase transition at around 4 GPa reduces the symmetry from rhombohedral to triclinic. Mössbauer spectra show that the complex becomes partially valence‐trapped after the second phase transition. This sluggish pressure‐induced valence‐trapping is in contrast to the very abrupt valence‐trapping observed when compound 1 is cooled from 130 to 120 K at ambient pressure.     

2，4-二氯苯氧乙酸构筑的三核锌(Ⅱ)配合物的合成、晶体结构及性能分析

以2,4-二氯苯氧乙酸(HL)和2,2′-联吡啶(2,2′-bipy)为配体合成了一个三核锌(Ⅱ)配合物[Zn3L6(2,2′-bipy)2]。该配合物晶体属三斜晶系,空间群P1,晶胞参数:a=1.073 85(6)nm,b=1.329 58(7)nm,c=1.515 80(10)nm,α=66.961 0(10)°,β=69.387 0(10)°,γ=72.992 0(10)°,V=1.833 77(19)nm3,Dc=1.656 g.cm-3,Z=1,μ(Mo Kα)=1.483 mm-1,F(000)=920,最终偏离因子R1=0.030 6,wR2=0.075 7。由于2,4-二氯苯氧乙酸根的桥联配位作用,配合物形成了三核结构。在该配合物的分子中,位于中间位置的锌(Ⅱ)离子的配位数是6,处于八面体配位环境中,而位于端位的2个锌(Ⅱ)离子的配位数都是5,处于三角双锥配位环境中。本工作还测定了标题配合物的磁性、荧光和电化学性能,结果表明:在28~300 K范围内,配合物有抗磁性;当激发波长为664 nm时,配合物在660 nm附近有1个强的荧光发射峰;在循环伏安过程中配合物的电子转移是准可逆的,对应的电极反应是Zn(Ⅱ)/Zn(0)。     

两个线形三核配合物的晶体结构及性质

合成并表征了2个新的线性三核配合物[Co₂^ⅢCo^ⅡL₂（μ-OAc）₄]（1）和[Ni₃L₂（μ-OAc）₂（CH₃OH）₂]·2H₂O（2）,其配体L为2-羟基-1,3-丙二胺和5-氟水杨醛缩合的产物。配合物1与DNA的作用通过紫外-可见光谱、荧光光谱、粘度实验和电化学方法进行了研究。紫外-可见光谱的结果表明配合物1与DNA的结合常数为2.43×10⁵ L·mol^-1。荧光光谱的研究结果表明配合物1能取代溴化乙锭和DNA结合,其淬灭常数为4.92×10³ L·mol^-1。配合物1和2的变温磁学性质研究表明在2个配合物的三金属中心之间均存在反铁磁性耦合。     

Investigation on Magnetic Properties of Exchange Coupled Transition Metal Complexes Ⅱ．Theoretical Model for Trinuclear Complexes

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N-苯甲酰基水杨酰肼为配体的三核镍(Ⅱ)配合物的合成与结构

N-苯甲酰基水杨酰肼配体(简写为H3Bzshz)与Ni(OAc)2·4H2O在不同的溶剂中反应得到2个三核镍配合物[Ni3(Bzshz)2(C5H5N)6](C5H5N)·CH3OH·2H2O(1)和[Ni3(Bzshz)2(OH)2(C2H6O)2]·2(C3H7NO)·0.5C2H6O(2).X射线衍射实验结果表明:化合物1属单斜晶系,空间群为P2(1)/n,晶胞参数a=2.198 9(2) nm,b=1.336 9(1) nm,c=2.503 4 nm,β=107.886(1)°,V=7.004(1) nm3,Z=4,R1=0.081 0,wR=0.215 4.3个Ni原子依次以八面体/八面体/平面正方形配位,其中Ni(1)…Ni(2)…Ni(3)原子间角是169.84(3)°,形成准直线形三核镍配合物;化合物2属三斜晶系,空间群为P-1,晶胞参数a=1.138 9(2) nm,b=1.368 2(2) nm,c=1.563 3(2) nm,α=67.190(2)°,β=83.953(2)°,γ=83.618(2)°,V=2.226 3(4) nm3,Z=2,R1=0.065 2,wR=0.188 0,而3个中心原子Ni(1)…Ni(2)…Ni(3)原子间角是180°,且依次以平面正方形/八面体/平面正方形相交替方式配位,具有中心对称的直线形结构.     

Synthesis,structure, magnetic properties and kinetics of formation of a cluster containing a {Cu3(μ3-OH)} core supported by a triazole-based ligand

The trinuclear copper complex, [Cu₃(μ₃-OH)(CTMB)₃(NO₃)₂(CH₃CN)₂]·5CH₃CN·H₂O (1) {CTMB = cyclohexotriazole-3-(4-methoxybenzamide)}, has been prepared by mixing Cu(NO₃)₂·2.5H₂O and CHMBH {CHMBH = N,N′-cyclohexane-1,2-diylidene-bis(4-methoxybenzoylhydrazide)} in acetonitrile under ambient conditions. Compound 1 was characterized by IR and UV–visible spectroscopies as well as elemental analyses. X-ray crystallography shows that the cluster contains a {Cu₃(μ₃-OH)} core supported by three triazole-based Schiff base ligands. Each Cu is bound to the 2-N of one triazole ring and the 1-N of another. However, the coordination sphere of each Cu is different, one is five-coordinate and the other two are six-coordinate and bridged by a NO₃ group. The six-coordinate sites are different, one has a terminal NO₃ and the other a MeCN ligand. Magnetic measurements revealed the presence of isotropic and antisymmetric exchange between the copper(II) centers. The data were analyzed using the Hamiltonian containing isotropic exchange for an isosceles triangle together with antisymmetric exchange: H = –J₁(S₁S₂ + S₂S₃)?J₂S₁S₃ + G[S₁ × S₂ + S₂ × S₃ + S₃ × S₁]. Compound 1 exhibits strong antiferromagnetic coupling with J₁ = ?180 and J₂ = ?118 cm^?1 and antisymmetric exchange with G_z = 15 cm^?1. Stopped flow spectrophotometric studies show that the formation of 1 occurs in three distinct phases and the kinetics of each phase has been determined.     

新型草酰胺大环Cu-Mn-Cu三核配合物的合成及其晶体结构

以草酰胺桥基配合物Cu L(H_2L=2,3-二氧-5,6∶13,14-二联苯基-9,10-环己基-1,4,8,11-四氮杂十四环-7,12-二烯烃)为前驱体,KSCN为辅助配体,Mn(ClO_4)_2为金属核心,经扩散反应合成了一种新型的大环三核金属配合物[Cu L(DMF)2]2Mn(SCN)2(1),其结构经UV-Vis,IR,元素分析,X-射线粉末衍射和X-射线单晶衍射表征。结果表明:1(CCDC:1535442)属三斜晶系,空间群P-1,晶胞参数a=9.951 0(19),b=11.188(2),c=13.907(3),α=69.960(3)°,β=83.727(4)°,γ=63.665(3)°,V=1 301.9(4)3,Z=1。     

Activation of Homolytic SiZn and SiHg Bond Cleavage,Mediated by a Pt0 Complex,via Novel PtZn and PtHg Compounds

The thermally stable [(tBuMe₂Si)₂M] (M=Zn, Hg) generate R₃Si^. radicals in the presence of [(dmpe)Pt(PEt₃)₂] at 60–80 °C. The reaction proceeds via hexacoordinate Pt complexes, (M=Zn ( 2 a and 2 b ), M=Hg ( 3 a and 3 b )) which were isolated and characterized. Mild warming or photolysis of 2 or 3 lead to homolytic dissociation of the Pt? MSiR₃ bond generating silyl radicals and novel unstable pentacoordinate platinum paramagnetic complexes (M=Zn ( 5 ), Hg ( 6 )) whose structures were determined by EPR spectroscopy and DFT calculations.