基于双核Cu(Ⅱ)-M(Ⅱ)[M=Pb和Cu]单元的氰基桥联配合物的合成、晶体结构和磁性研究(英文)

四个氰基桥联的杂金属配合物{[CuPb(L1)][FeⅢ(bpb)(CN)2]}2·(ClO4)2·2H2O·2CH3CN (1), {[CuPb(L1)]2- [FeⅡ(CN)6](H2O)2}·10H2O (2), {[Cu2(L2)][FeⅢ(bpb)(CN)2]2}·2H2O·2CH3OH (3)和{[Cu2(L2)]3[FeⅢ(CN)6]2(H2O)2}· 10H2O (4)是通过 K[FeⅢ(bpb)(CN)2] [bpb = 1,2-双(吡啶-2-羧酰氨基)苯二价阴离子]和 K3[FeⅢ(CN)]6 与双核大环席夫碱化合物 [CuPb(L1)]-(ClO4)2或[Cu2(L2)]·(ClO4)2. H2L1配体是由 2,6-二甲基对甲基苯酚、乙二胺和乙二烯三乙胺以1:1:1摩尔比缩合得到, 而H2L2配体是由2,6-二甲基对甲基苯酚和丙二胺以1:1摩尔比缩合得到. 单晶X 射线衍射分析揭示了化合物 1 是一个由[FeⅢ(bpb)(CN)2]-阴离子和[CuPb(L1)]2+阳离子交替排列形成的环状杂三金属分子结构. 化合物 2 是一个[Fe(CN)6]4-离子和两个[Cu2L2]2+阳离子构成的哑铃型五核分子结构, 该单元通过分子间氢键形成了二维超分子结构. 双杂金属配合物 3 是一个由中心对称的[Cu2(L2)]2+部分与两个含有氰基的 [FeⅢ(bpb)(CN)2]-离子构筑四核分子. 八核化合物 4 是由两个[Fe(CN)6]3-离子连接了三个[Cu2(L2)]2+离子构筑而成. 磁性调查揭示了化合物 1、3 和 4 都表现出整体的反铁磁行为.

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

Synthesis, crystal structure and magnetic properties of novel copper compound Cu(phen)(m-CBA)_2

A novel compound Cu（phen）（m-CBA）2 was synthesized with m-chlorobenzoic acid（m-CBA）, 1,10-phenanthroline（phen） and Cu（OAc）2·H2O. It was characterized by IR, UV, elemental analyses and X-ray crystallography. It crystallizes in the monoclinic crystal system with C2/c space group, a=2.9699（4） nm, b=1.15452（2） nm, c=1.5335（2） nm, β=111.118（2）°, V=4.905 1（1） nm3, Z=8, F（000）=2 328, R1=0.072 8, wR2=0.223 4 [I2σ（I）]. Structure analysis shows that the copper center coordinates with two nitrogen atoms from one 1,10-phenanthroline molecule, two oxygen atoms from two m-chlorobenzoic acid molecules, giving a distorted squared planar coordination geometry. This novel compound shows paramagnetic interactions between copper centers.

Crystal Structure and Magnetic Property of 2-（Imidazo[1,2-α]pyri-din-2-yl）- 2-oxoacetic Acid and Its Perchlorate

We herein report two crystals based on 2-（imidazo[1,2-a]pyridin-2-yl）-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-（imidazo[1,2-a]pyridin-2-yl）- 2-oxoaeetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions （hydrogen bonds, anion-Tr or lone- pair-~r interactions）, leading to low magnetic susceptibilities. 2-（imidazo[1,2-a]pyridin-2-yl）- 2-oxoaeetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional double- stranded chain structure assembled through double hydrogen bonds and anion-To interactions, and reveals weak ferromagnetism.

Structural, Magnetic and Optical Properties of BiFe1-xNbxO3

Nb doped multiferroic BiFe1-xNbxO3 （0 〈x 〈0.05） polycrystalline powders have been syn-thesized by using a sol-gel method. The effect of Nb dopant on the structural, magnetic and optical properties is investigated. According to the X-ray di raction data and the result of Rietveld re nement, all the samples maintain the R3c phase, while the lattice parameters a, c, the cell volume V and the Fe-O-Fe bond angle change. The remnant magnetization enhances by appropriate Nb doping due to the decreasing of the grain size. Meanwhile, Nb dopant leads to the narrowing of the band gap of BiFe1-xNbxO3 samples.

Syntheses, Structures and Magnetic Properties of Two Co(II) Coordination Polymers with 2,5-Pyridine Dicarboxylic Acid

The hydro(solvo)thermal reactions of cobalt powder or its chloride with 2,5- pyridine dicarboxylic acid (H2PYDC) yielded two new complexes: [Co(II)2(PYDC)2(H2O)2- (H2O)4]n 1 and {Co(II)[NH2(CH3)2]2(PYDC)2}n 2. It is observed that the reactive solvents result in different connectivity modes of ligand and diverse dimensional extension of crystal structures. The correlation between structure and magnetic property will be discussed in this paper. Crystal data for 1: space group P1, a = 7.0419(17), b = 8.937(2), c = 9.6182(19) ?, α = 91.532(4), β = 99.869(10), γ = 107.889(11)o, V = 565.5(2) ?3, Z = 1, Dc = 1.845 g/cm3, μ = 1.56 mm-1, F(000) = 322 , R = 0.0505 and wR = 0.1580; and those for 2: space group C2/c, a = 14.9075(6), b = 8.2523(3), c = 16.9643(2) ?, β = 100.982(2)o, V = 2048.75(11) ?3, Z = 4, Dc = 1.560 g/cm3, μ = 0.892 mm-1, F(000) = 996, R = 0.0443 and wR = 0.1134.

Novel Synthesis Method of Nonst0ichiometric Na2-xlrO3 Crystal Structure, Transport and Magnetic Properties

Transition metal oxides with 4d or 5d metals are of great interest due to the competing interactions, of the Coulomb repulsion and the itineracy of the d-electrons, opening a possibility of building new quantum ground states. Particularly the 5d metal oxides containing Iridium have received significant attention within the last years, due to their unexpected physical properties, caused by a strong spin orbit coupling observed in It（IV）. A prominent example is the Mott-insulator Sr2IrO4. Another member of this family, the honeycomb lattice compound Na2IrO3, also being a Mott-insulator having, most probably, a Kitaev spin liquid ground state. By deintercalating sodium from Na2IrO3, the authors were able to synthesize a new honeycomb lattice compound with more than 50% reduced sodium content. The reduction of the sodium content in this layered compound leads to a change of the oxidation state of iridium from ＋ IV to ＋ V/＋ VI and a symmetry change from C2/c to P-3. This goes along with significant changes of the physical properties. Besides the vanishing magnetic ordering at 15 K, also the transport properties changes and instead insulating semiconducting properties are observed.

Synthesis and Structure of Paramagnetic β-OctamolybdateComplex, [Fe(2,2'bipy)_3]_2[Mo_8O_26]·6H_2O

A novel octamolybdate complex, [Fe(2,2?bipy)3]2[Mo8O26]6H2O has been synthesized via the hydrothermal technique, and it crystallizes in monoclinic, space group P21/c with two molecules in a unit cell: a = 1.21512(5), b = 1.36840(5), c = 2.18823(9) nm, b = 90.515(1), Mr = 2340.42, Z = 2, V = 3.6384(2) nm3, Dc = 2.136 g/cm3, F(000) = 2296, l(MoKa) = 0.071073 nm, = 1.813 mm-1, R = 0.0719 and wR = 0.1093 for 4058 observed reflections with I≥2s(I). The structure is characterized by the co-existence of octahedral [Fe(2,2?bipy)3]2+ cations and b-octamolybdate [Mo8O26]4- anions. The magnetic susceptibility data show a Curie-Weiss paramagnetic behavior (q = -5.201 K) in accordance with the spin-only ground state of FeⅡ ions. IR, UV-Vis, and EPR spectra are also briefly noted in this paper.

Synthesis,structure,and magnetic property of a cobalt(Ⅱ)complex based on pyridyl⁃substituted imino nitroxide radical

A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,elemental analysis,IR,and magnetic properties.X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB-ligands.The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ)and im4-py radical.The magnetic property is explained by the magnetic and structure exchange mechanism.CCDC:976028.

Construction of three high-nuclearity heterometallic cluster organic frameworks by introducing a bifunctional tripodal alcohol ligand

Three new metal organic frameworks,[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)O_(2)(4-thmpy)_(4)(O_(2)CPh)_(10)(OMe)_(2)(H_(2)O)_(2)]·3CH_(3)OH·4H_(2)O(1),[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·CH_(3)OH·3H_(2)O(2),and[Mn^(Ⅱ)_(4)Ni^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·2CH_(3)OH·2H_(2)O(3),have been successfully synthesized by using 4-[tri-(hydroxymethyl)methyl]pyridine(4-thmpyH_(3))as ligand.Crystal structure analyses show that compound 1 is a disk-like twelve nuclear[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)]0D cluster.Compounds 2 and 3 are isomorphic,and the decanuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]node in compound 2 can be seen as a hyper-tetrahedron of four coboundary cubic alkanes[Mn^(Ⅱ)Co^(Ⅱ)_(3)O_(4)],then each ten-nuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]is connected by six 4-thmpy^(3-)with six adjacent decanuclear clusters[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)],forming the NaCl-type 3D topological structure.Magnetic studies showed that there exist antiferromagnetic interactions between metal ions in 1-3.

Synthesis, structure, and magnetic properties of a cyanide-bridged Fe(Ⅲ)-Cu(Ⅱ) bimetallic double-zigzag chain with slow relaxation of the magnetization

Using Bu4N[Fe(Tp*)(CN)3]- (Tp* = hydrotris(3,5-dimethylpyrazol-l-yl)borate) as the building block to react with Cun and N-methylimidazole, we obtained a one-dimensional (1D) beterobimetallic cyano-bridged chain, [Fe(Tp*)(CN)3]2Cu(N- methylimidazole)2.2H20 (1). The crystal structures and magnetic studies demonstrate that complex 1 exhibits slow relaxation of the magnetization due to strong intrachain ferromagnetic coupling and weak interchain interactions.

Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique

The transparent semiconductors of Ti and Ga-incorporated ZnO(TGZO) thin films were prepared by radio frequency(RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the(002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum(FWHM) of 1.76×10^(-3) rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc's relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier's dispersion model.

Structure,magnetic properties and magnetocaloric effects of Fe_(50)Mn_(15-x)Co_xNi_(35) alloys

FesoMn15-xCoxNi35 （x=0, 1, 3, 5, 7） alloys were prepared by arc melting under purified argon atmosphere. The ingots were homogenized at 930℃ for 90 h followed by water quenching. The crystal structure, magnetic properties and magnetocaloric effects of the alloys were studied by X-ray diffraction （XRD） and MPMS-7-type SQUID. The results show that all samples still maintained a single γ-（Fe, Ni）-type phase structure. With the increase of the content of Co, the Curie temperatures of these alloys increased and exhibited a second-order magnetic transition from ferromagnetic （FM） to paramagnetic （PM） state near Curie temperature. The maximum magnetic entropy change and the relative cooling power of Fe50Mn10CosNi35 alloy was 2.55 J/kg.K and 181 J/kg, respectively, for an external field change of 5 T. Compared with rare earth metal Gd, FesoMnls-xCoxNi35 series of alloys have obvious advantage in resource price; their Curie temperatures can be tuned to near room temperature, maintain a relatively large magnetic entropy change at the same time and they are a type of potential magnetic refrigeration materials near room temperature.

Cyanide-bridged complexes based on dinuclear Cu(Ⅱ)-M(Ⅱ) [M=Pb and Cu] building blocks: Synthesis, crystal structures and magnetic properties

Four cyanide-bridged heterometallic complexes { [CuPb（L1）][FenI（bpb）（CN）2] }2-（C104）2.2H20.2CH3CN （1）, { [CuPb（LI）]2[FeII （CN）6]（HzO）z}＇10H20 （2）, {[Cu2（L2）][Fent（bpb）（CN）2]2}＇2H20＇2CH3OH （3） and {[Cu2（L2）]3[FeIII（CN）6]z（H20）2}-10H20 （4） have been synthesized by treating K[Fem（bpb）（CN）2] [bpb2-=l,2-bis（pyridine-2-carboxamido）benzenate] and K3[Feln（CN）]6 with dinuc[ear compartmental macrocyclic Schiff-base complexes [CuPh（LI）].（C104）2 or [Cu2（L2）]-（CIO4）2, in which H2LJ was derived from 2,6-diformyl-4-methyl-phenol, ethylenediamine, and diethylenetriamine in the molar ratio of 2：1：1 and H2L2 from 2,6-diformyl-4-methyl-phenol and propylenediamine in the molar ratio of 1：1. Single crystal X-ray diffraction analysis reveals that compound 1 displays a cyclic hexanuclear heterotrimetallic molecular structure with alternating [Fem（bpb）（CN）2]- and [CuPb（L＋）]2＋ units. Complex 2 is of a neutral dumb-bell-type pentanuclear molecular configuration consisting of one [Fe（CN）6]4- anion sandwiched in two [CuPu（L1）]2＋ cations, and the pentanuclear moieties are further connected by the hydro- gen bonding to give a 2D supramolecular framework. Heterobimetallic complex 3 is a tetranuclear molecule composed of a centrosymmetric [Cuz（L2）]2＋ segment and two terminal cyanide-containing blocks [Fetn（bpb）（CN）2]-. Octanuclear compound 4 is built from two [Fe（CN）6]3- anions sandwiched in the three [Cu2L2]2＋ cations. Investigation of their magnetic properties reveals the overall antiferromagnetic behavior in the series of complexes except 2.

Structural and magnetic properties of CeZnAl3 single crystals

We have synthesized single crystals of CeZnAl3, which is a new member of family of Ce-based intermetallics CeTX3 （T=transition metal, X=Si, Ge, A1）, crystallizing in the non-centrosymmetric tetragonal BaNiSns-type structure. Magnetization, specific heat and resistivity measurements all show that CeZnAls orders magnetically below around 4.4 K. Furthermore, magnetization measurements exhibit a hysteresis loop at low temperatures and fields, indicating the presence of a ferromagnetic component in the magnetic state. This points to a different nature of the magnetism in CeZnAl3 compared to the other isostructural CeTAl3 compounds. Resistivity measurements under pressures up to 1.8 GPa show a moderate suppression of the ordering temperature with pressure, suggesting that measurements to higher pressures are required to look for quantum critical behavior.