Studies on Binuclear Co(II) and Cu(II) Complexes of Tridentate N-(2-Carboxyphenyl)Salicylideneimine

Homo Cu(II) and Co(II) binuclear complexes H[MLClMCl₂] formed by using the donor properties of the cis two oxygen atoms of the tridentate N-(2-carboxyphenyl)-salicylaldimine Schiff base derived from salicylaldehyde and anthranilic acid have been synthesized. It was found that the Cu(II) “complexed ligand” readily reacts with CoCl₂ to form mononuclear Co(II) and binuclear oxygen bridged Co(II) complex [Co₂-L₂](H₂O)₂. The structure of the so prepared complexes was investigated using microchemical analysis, molar conductance measurements as well as electronic and vibrational spectral studies. It was concluded that in the Cu(II) binuclear complex, the Cu(II) ion inside the “complexed ligand” has a planar structure while the other Cu(II) ion is distorted away from planarity. In the Co(II) binuclear complex, the Co atom of the “complexed ligand” is distorted from tetrahedral structure when it coordinates to the second Co atom.     

3,4-二甲氧基苯乙酸邻菲啰啉镱(III)配合物的合成、晶体结构及荧光光谱

合成了3,4-二甲氧基苯乙酸邻菲啰啉镱(III)配合物(C84H82Yb2N4O24): [Yb2(DMPA)6(phen)2](HDMPA=3,4-二甲氧基苯乙酸(C12H12O4), phen=1,10-邻菲啰啉)(CCDC: 757541), 并通过元素分析、红外(IR)光谱、热重分析(TG-DTG)对其进行了表征, 用单晶X射线衍射测定了配合物的晶体结构. 配合物C84H82Yb2N4O24属三斜晶系, 空间群P1, 晶胞参数: a = 1.22877(14) nm, b=1.23235(16) nm, c=1.45234(19) nm, α=91.726(7)°, β=103.321(7)°, γ=113.885(6)°, 晶胞体积: V=1.9379(4) nm3, 晶胞内分子数Z=1, 相对分子质量Mr=1877.62, 电子数F(000)=946, 密度Dc=1.609 g·cm-3, 吸收系数μ(Mo Kα)=2.481 mm-1. 测定了铕和铽掺杂(2.5%, 5.0%, 10.0%, 摩尔分数)的配合物的荧光光谱, 结果表明, 单独的配体没有荧光, 在形成配合物后, 依然显示铕(III)离子和铽(III)离子的特征发射峰, 这表明配体将吸收的能量有效地转移给了中心离子, 配体起到了很好的敏化作用.     

Synthesis,crystal structure,and luminescence of a quaternary binuclear europium complex [Eu2(phth)2(Hphth)2(phen)2(H2O)4]

A quaternary binuclear europium complex [Eu₂(phth)₂(Hphth)₂(phen)₂(H₂O)₄] (H₂phth?=?phthalic acid, phen?=?1,10-phenanthroline) has been synthesized. The structure was determined by X-ray crystallography which reveals that it is binuclear with each europium nine-coordinate. Intermolecular hydrogen bonds link the complex units to form a 3D supermolecular network. Its properties have been studied by means of luminescence spectrum and thermal analysis. Fluorescence spectra show that the complex exhibits strong red emission.     

Synthesis and Crystal Structure of Binuclear Silver(Ⅰ)Complex with 2-nitro-(2-pyridylsulfanylmethyl)benzene

The reaction of 2-nitro-(2-pyridylsulfanylmethyl)benzene L with silver nitrate produces a centrosymmetric binuclear complex bis(2-nitro-(2-pyridylsulfanylmethyl)benzene-N,S)-bis(nitrato-O,O)-disilver(Ⅰ), [AgLNO3]2 1. The crystal is of triclinic, space group P1, with a = 7.383(3), b = 8.340(3), c = 12.003(4) A, a = 95.069(6), β = 93.498(5), γ = 102.734(6)°, C24H2oAg2N6-O10S2, Mr= 832.32, V= 715.6(4) A3, Z = 1, Dc = 1.931 g/cm3, F(000) = 412, μ = 1.581 mm-1, R=0.0351 and wR = 0.0749 Each silver atom is tetrahedrally coordinated by two O atoms from bidentate nitrate, one S atom from a ligand and one N atom from another ligand. Furthermore, AgAg interactions have been observed in the complex.     

Synthesis,crystal structure and magnetic properties of a dinuclear manganese(III) tetradentate Schiff-base complex

A dinuclear manganese(III) tetradentate Schiff-base complex, [Mn₂(salophen)₂(4,4′-bipy)₃](BPh₄)₂ (1) (salophen = N,N′-o-phenylene-bis(salicylideneaminato)), has been synthesized and structurally characterized. Compound 1 crystallized in the triclinic, P 1 space group, a = 13.431(4), b = 13.791(4), c = 13.886(4) Å, α = 73.599(5)°, β = 80.410(6)°, γ = 71.241(5)°, V = 2328.3(12) ų. Complex 1 contains two Mn(salophen) moieties bridged by 4,4′-bipy to form a dinuclear unit, with two terminal 4,4′-bipy ligands. Variable temperature magnetic susceptibility (2–300 K) shows very weak ferromagnetic interactions between the Mn(III) ions.     

Synthesis, structure, magnetic and spectroscopic properties of chromium(III) complex with quinoline-2-carboxylate ion

The new complex of chromium (III) with quinoline-2-carboxylate ion, [Cr(quin-2-c)₂ClMeOH]·MeOH (1), has been synthesized and its structure has been established by single crystal X-ray diffraction studies. The spectroscopic (IR, UV-Vis) and magnetic study have been undertaken. The chromium ion is coordinated by ClN₂O₃ donor set of pseudoctahedral geometry. The structure of 1 consists of hydrogen-bonded dimers which are further connected by weaker C-H?O bonds and C-H?Cl interactions into the layers. The layers are held together by the aromatic π?π contacts. The electronic experimental energies of d-d transitions are comparable with values calculated for crystal field parameters Dq = 1669, Ds = 705, and B = 684 cm⁻¹. The splitting of the d-d bands was observed by applying the filtration process. Magnetization measurements revealed the occurrence of weak antiferromagnetic interactions together with zero field splitting effects. The appearance of magnetic exchange between distant Cr(III) ions (Cr?Cr separation >6 Å) was ascribed to hydrogen bond extension of carboxylate ligands.     

Synthesis and Crystal Structure of Binuclear Silver(I) Complex with 2-nitro-(2-pyridylsulfanylmethyl)benzene

1 INTRODUCTION Metallosupramolecular species with metal-metal interactions have been designed and synthesized due to their potential applications as functional materi- als[1]. For Ag(I) coordination compounds, short Ag(I) –Ag(I) separations have been found in many bi- and polynuclear complexes[2~4], and these short metal- metal distances have been attributed to the ligand ar- chitecture[5, 6]. Thus, the rational design of bi- and polynuclear Ag(I) complexes must recognize the in- here…     

A one-dimensional azido-bridged manganese(III) complex with bidentate Schiff base: Crystal structure and magnetic properties

The synthesis, structural characterization, and magnetic behavior of a novel one-dimensional azido-bridged manganese(III) complex of formula [Mn(L)₂N₃] (1) is reported, where HL is the bidentate Schiff base obtained from the condensation of salicylaldehyde with 4-methoxy aniline. Complex 1 crystallizes in the monoclinic system, space group P2₁/n, with a=11.743(4) Å, b=24.986(9) Å, c=13.081(5) Å, β=95.387(7)° and Z=2. The complex is of one-dimensional chain structure with single end-to-end azido bridges and the manganese(III) ion has an elongated octahedral geometry. Magnetic studies show that the weak antiferromagnetic interaction is mediated by the single end-to-end azido bridge with the exchange parameter J=−5.84 cm⁻¹.     

[Eu2(TCM)2(DMSO)6]·2DMSO双核笼状稀土配合物的合成与结构

报道一个H3TCM配体在较小尺寸的溶剂DMSO中与稀土离子Eu3+通过自组装形成的双核笼状结构, 从中可进一步看出溶剂分子的尺寸对该双核结构的影响.     

5-溴水杨醛缩乙醇胺Schiff碱Cu(II)配合物的合成和晶体结构

The title complex Cu(L)₂ [HL=N-(5-bromosalicylidene)-2-aminoethanol] was synthesized by the reaction of Cu(CH₃COO)₂·H₂O with N-(5-bromosalicylidene)-2-aminoethanol in the ethanol. It was characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The crystal of the title complex [Cu(C₉H₉BrNO₂)₂] belongs to monoclinic, space group P2₁/n with a=1.319 1(5) nm, b=0.444 58(16) nm, c=1.656 7(6) nm, β=91.226(5)°, V=0.971 46(6) nm³, Z=2, D_c=1.879 Mg·m^-3, μ=5.264 mm^-1, F(000)=542, and final R₁=0.045 6, wR₂=0.097 0. The complex comprises a four-coordinated copper(II) center, with an N₂O₂ planar coordination environment. The molecules are connected by hydrogen bonds to form two-dimensional layered structure. CCDC: 274180.     

Synthesis,crystal structure and properties of a novel copper(II) complex with tripod ligand tris(1H-benzimidazol- 2-ylmethyl)amine

A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H₂O)] (C1O₄)₂?·?C₅H₄N₂O₃?·?H₂O (C₅H₄N₂O₃?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C ₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g ₂?<?g _ζ and a very small value of A ₂ (20?×?10^?4?cm^?1).     

2,4,6-三甲基苯甲酸和1,10-邻菲啰啉双核铽配合物的合成和晶体结构

A binuclear terbium complex with 2,4,6-Trimethylbenzoate and 1,10-phenanthroline, [Tb₂(TMBA)₆(Phen)₂], has been synthesized (TMBA=2,4,6-Trimethylbenzoic acid and phen=1,10-phenanthroline) and characterized by IR, elemental analysis and X-ray diffraction methods. The title complex crystallizes in monoclinic system, space group P2₁/c with a=1.327 5(2) nm, b=2.817 9(5) nm, c=1.282 5(2) nm, β=116.692(3)°, V=4.286 2(13) nm³, Z=4，D_c=1.423 g·cm^-3. There are four bridged carboxylate groups of the 2,4,6-trimethylbenzoic acid bonded to the two terbium ions, each ions is also chelated with the two oxygen atoms of a molecule of the 2,4,6-trimethylbenzoic acid and the two nitrogen atoms of a 1,10-phenanthroline respectively, forming a 8-coordination distorted square antiprism. Average Tb-O and Tb-Ndistance of the two Tb(Ⅲ) ions are equal respectively. This shows the two terbium ions are in the same chemical enviorments. The complex emits intense green fluorescence under ultraviolet light. CCDC: 619215.     

Synthesis,crystal structure and electronic properties of bis(N-2-bromophenyl-salicydenaminato)copper(II) complex

A new series of complexes of the type bis(N-substituted-salicydenaminato)copper(II) (1–9), have been synthesized and characterized by IR, UV–Vis and elemental analysis methods. The molecular structure of bis(N-2-bromophenyl-salicydenaminato)copper(II) (6), was determined using X-ray crystallography. There are two independent molecules in the structure. Each shows a neutral, mononuclear, four-coordinate, square-planar trans-Cu[N₂O₂] geometry and, in each, the Cu atom and the ligating atoms are coplanar. The chelating N–Cu–O angle is 91.39(11)° for molecule one and 91.20(11)° for molecule two, whereas the non-chelating N–Cu–O angles are 88.61(11) and 88.80(11)°, respectively. The trans-N–Cu–N and trans-O–Cu–O bond angles are 180°. The electronic absorption spectra of copper(II) complexes (1–9), indicate that the d–d band energy is dependent on the nature and position of substituent on phenyl ring of the salicyldenimine ligand. The UV–Vis spectra in various solvents were measured and a relationship between absorption spectra and dielectric constant of the solvents is reported.     

Preparation, Characterization and Properties of Two New Lanthanide(III)-5-(2-pyridyl)tetrazolate Complexes

Two new mononuclear lanthanide(III) complexes Ln(pytz)3(H2O)3·(H2O)3.5[Ln=Tb(1); Eu(2); Hpytz= 5-(2-pyridyl)tetrazole] were synthesized by reacting Hpytz with the corresponding lanthanide(III) ions and characterized. The single crystal X-ray diffraction analysis reveals that complexes 1 and 2 are isostructural and the lanthanide(III) ions in both complexes 1 and 2 are nine-coordinated, with three oxygen atoms of three coordination water molecules and six nitrogen atoms of three pytz ligands, forming a monocapped square antiprism. Extensive hydrogen bonds exist, resulting in a three-dimensional supramolecular network structure by hydrogen-bonds in both complexes 1 and 2, respectively. Complex 1 exhibits typical green fluorescence of Tb(III) ion and complex 2 red fluorescence of Eu(III) ion, in solid state at room temperature.     

Synthesis,crystal structure,and magnetic properties of a linear trinuclear Cu(II) complex

A new linear trinuclear Cu(II) complex, [Cu₃(NTA)₂(4,4′-bpt)₄(H₂O)₂]?·?10H₂O (H₃NTA?=?nitrilotriacetic acid, 4,4′-bpt?=?4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) (1), was obtained from evaporation of an aqueous solution containing Cu(NO₃)₂?·?6H₂O, 4,4′-bpt, nitrilotriacetic acid (H₃NTA), and NaOH. 1 was characterized using single-crystal X-ray diffraction, IR, and elemental analysis. In the trimer, the three linear copper ions are bridged by two NTA carboxylate groups in a syn–anti conformation and connected by 4,4′-bpt to produce a 1-D array. Temperature-dependent magnetic susceptibilities reveal the presence of weak antiferromagnetic exchange between metal centers.     

A Schiff base N-(2-hydroxylacetophenone)-3-oxapentane-1,5-diamine and its copper(II) coordination polymer: synthesis,crystal structure,antioxidation, and DNA-binding properties

A Schiff base, N-(2-hydroxylacetophenone)-3-oxapentane-1,5-diamine (HL) and its Cu(II) coordination polymer, [Cu(L)(NO₃)] _n , have been synthesized and characterized. [Cu(L)(NO₃)] _n is a 1?:?1 (Cu?:?L) polymer, in which copper is six-coordinate with distorted octahedral geometry. The polymer has a 1-D infinite chain structure in which coppers are bridged by a single nitrate. The interaction of HL and complex with calf thymus DNA (CT-DNA) has been investigated; the linear Stern–Volmer quenching constants (K _SV) suggest that the two compounds bind to DNA via intercalation. The binding affinity of complex was higher than HL. Antioxidant assay in vitro shows that the Cu(II) complex possesses significant antioxidant activities.     

Synthesis,crystal structure and ferromagnetic interactions of a silver(I) complex with imizadolyl-substituted nitroxide radicals

A silver(I) complex with nitronyl nitroxide, [Ag₂(NIT-R)₄(NO₃)₂]?·?CH₃OH [NIT-R?=?2-(5-methylimidazol-4-yl)-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-3-oxide], has been prepared and characterized by magnetic and single-crystal X-ray diffraction studies. In the complex, the silver(I) ion is coordinated with two monodentate nitronyl nitroxide radicals by the nitrogen of the imizadole ring. The silver(I) ion is two-coordinate and forms a dimer through Ag?···?Ag weak metal bonding interactions. The magnetic properties for the title complex have been investigated in the temperature range 2?～?300?K showing ferromagnetic interactions between the coordinated nitronyl nitroxides (J?=?3.64?cm^?1) and intermolecular antiferromagnetic interactions.     

Palladium(II) Complexes of N-(2-Thienylmethylidene)aniline Derivatives

Coordination reactions of N-(2-thienylmethylidene)aniline derivatives, L, with PdCl₂ or [PdCl₄]^2? in ethanol yield stable complexes of the type trans-(L)₂PdCl₂ with the azomethine nitrogen atoms as σ donors. These are not readily convertible to othor-palladated complexes. An X-ray crystallographic study of the complex (L₂)₂PdCl₂ reveals a centrosymmetric geometry. The structure is in the triclinic space group $ {\rm P}\bar 1 $ with a = 8.633(2) Å, b = 12.759(3) Å, c = 8.398(2) Å, α = 96.65(5)°, β = 111.47(5)*, γ= 101.28(6)°, and Z = 1. The final R factor is 0.043 (Rw = 0.044) for 2396 observed reflections. There is no real bonding between a thiophene sulfur atom and a central palladium ion. However, a long distance interaction between S and Pd does exist.     

Synthesis,structure and magnetic properties of a Pr(III) complex with chelating nitronyl nitroxide radicals

The synthesis and structure of Pr(III) complex with chelating nitronyl nitroxide radicals of formula [Pr(III)(NIT2Py)₂(NO₃)₃] (NIT2Py?=?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) is reported. Pr(III) is ten-coordinate with three bidentate nitrate anions and two radicals. The radical behaves as a bidentate chelating ligand through one oxygen atom of the nitronyl nitroxide group and one nitrogen atom of a pyridine ring. The electronic spectrum for the complex in THF and magnetic susceptibilities from 77–300?K are reported.