二维层状聚合物{[Mn3(btc)(Hbtc)(H2btc)(H2O)6]·6H2O}n的合成

利用蒸气扩散法合成了1,3,5-苯三酸与锰(Ⅱ)的二维层状聚合物{[Mn3(btc)(Hbtc)(H2btc)(H2O)6]·6H2O}n(H3btc=1,3,5-苯三酸).通过X射线单晶衍射、元素分析和红外光谱对其结构进行了表征.中心离子Mn(Ⅱ)处于扭曲的八面体配位环境中,来自btc同一个羧基的两个氧原子,和分别来自Hbtc、H2btc的两个氧原子占据赤道平面,两个配位水的氧原子占据轴向位置.     

Crystal structure of the inverse weberite ZnFeF5(H2O)2, magnetic and mössbauer study of the antiferromagnet ZnFeF5(H2O)2 and ferrimagnet Mn FeF5(H2O)2

The room temperature crystal structure of the inverse weberite ZnFeF₅ (H₂O)₂ is refined from powder X-ray diffraction. The cell is orthorhombic (S.G. Imma, a = 7.475(1) →A, b = 10.766(1) →A, c = 6.594(1) →A, z = 4). Below T_N = 9(2) K, ZnFeF₅(H₂O)₂ becomes a 1-D antiferromagnet. This behaviour was characterized by susceptibility and magnetization measurements and Mössbauer spectroscopy. On the contrary, isotypic MnFeF₅(H₂O)₂ is confrimed to be a ferrimagnet below T_c = 39.5(1)K. Its magnetic and Mössbauer characteristics are, above and below T_c,and agree with a 3-D magnetic character. Ferrimagnetism could be due to frustration effects as in previously described Fe₂F₅(H₂O)₂.     

Growth and characterization of Catena-((μ4-dihydrogen oxalate)-bis(μ3-hydrogen oxalato)-(μ2-dihydrogen oxalate)-tetra-aqua-di-rubidium) {Rb(HC2O4)(H2C2O4)(H2O)2}1∞ single crystal for nonlinear optical applications

A versatile, optically active, metal organic frame work, Catena-((μ₄-dihydrogen oxalate)-bis(μ₃-hydrogen oxalato)-(μ₂-dihydrogen oxalate)-tetra-aqua-di-rubidium) {Rb(HC₂O₄)(H₂C₂O₄)(H₂O)₂}¹∞ (CDBDTR), was grown by the process of slow evaporation using water as the solvent. Single XRD showed that the crystal belongs to the triclinic crystal system with the space group P1. The assigned vibrational frequencies of the compound were identified by the FTIR and FT-Raman techniques. The UV–Vis spectrum revealed the cut off wavelength of the crystal to be 233 nm, and due to this low cut off, it occupies a place in optoelectronic devices. Using the UV-spectra, several optical constants were assessed. The surface morphology was studied using HR-SEM analysis. Energy dispersive X-ray analysis (EDXA) confirmed the presence of rubidium in the crystal. The thermal stability of the crystal was investigated using TG/DTA analysis. The dielectric response of the grown crystal has been thoroughly analysed. A photoluminescence study showed that the crystal has a high degree of luminescence, and its single peak emission affirms its highly ordered crystalline nature. The life time was also analysed. The crystal offers adequate resistance to laser radiation with a threshold value of 4.78 GW/cm². By the Kurtz–Perry technique, the second harmonic generation of the crystal was assessed. The third order nonlinearity was explored using the Z-Scan technique. The figures of merit W and T were calculated in order to find the aptness of the crystal as a promising candidate for optical switching and optical limiting applications.     

钴配合物[Co(phen)(pydc)(H2O)]·2H2O的合成、表征及荧光性质

采用溶剂挥发法合成了钴配合物[Co(phen)(pydc)(H2O)]· 2H2O,通过元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射对其结构进行了表征.该化合物属于三斜晶系,Pi空间群.六配位的Co(Ⅱ)为畸变的八面体构型.单胞分子间通过氢键及π-π堆积作用相互形成三维网状结构.荧光测试表明配合物在369nm(λmax)具有强的荧光发射.     

[Fe3O(Ala)6(H2O)3](ClO4)7和[Fe3O(Gly)6(H2O3)(NO3)7)·3H2O]顺磁共振谱及变温磁化率研究

本文通过对[Fe 3O(Ala) 6(H 2O) 3](ClO 4) 7和[Fe 3O(Gly) 6(H 2O) 3](NO 3) 7·3H 2O的ESR谱的解析及变温磁化率的研究,得出它们的ESR谱具有各向同性的特点;朗德因子分别为2.019和1.997;两种配合物中铁离子间有反铁磁相互作用.     

Synthesis, Crystal Structure and Luminescent Property of Complex [Tb0.1Gd0.9(TPTZ)(H2O)6]Cl3·3H2O

The complex [Tb_0.1Gd_0.9(TPTZ)(H₂O)₆]Cl₃·3H₂O was prepared through the reaction of 2,4,6-tris-(2-pyridyl)-1,3,5-triazine (TPTZ) with TbCl₃:GdCl₃ (0.1:0.9) in absolute ethanol at room temperature. Single crystal X-ray diffraction revealed that the metal atom is nine-coordinated with three nitrogen atoms from one TPTZ ligand and six oxygen atoms from six water molecules. The complex emits intense green fluorescence under ultraviolet light. The luminescence peaks correspond to the characteristic emission ⁵D₄→⁷F_J (J = 3–6) transitions of the Tb³⁺ ion.     

Syntheses and structure characterization of inorganic/organic coordination polymers: Ag(dpa), Co(O3PH)(4,4′-bpy)(H2O), Zn(O3PH)(4,4′-bpy)0.5 and Mn[O2PH(C6H5)]2(4,4′-bpy) (dpa=2,2′-dipyridylamine; 4,4′-bpy=4,4′-bipyridine)

Four novel coordination polymers: Ag(dpa) I, Co(O₃PH)(4,4′-bpy)(H₂O) II, Zn(O₃PH)(4,4′-bpy)_0.5 III and Mn[O₂PH(C₆H₅)]₂(4,4′-bpy) IV (dpa=2,2′-dipyridylamine; 4,4′-bpy=4,4′-bipyridine), were synthesized by microwave heating and characterized by X-ray crystallography. I crystallizes in monoclinic space group P21/n with a=11.576(2) Å, b=5.585(2) Å, c=15.243(4) Å, β=109.00(2)°, V=931.8(3) ų. II crystallizes in monoclinic Cc space group with a=22.477(7) Å, b=5.280(1) Å, c=10.404(4) Å, β=96.08(3)°, V=1227.8(7) ų. III crystallizes in monoclinic P21/c space group with a=9.758(2) Å, b=7.449(3) Å, c=10.277(2) Å, β=100.02(2)°, V=735.6(4) ų. IV crystallizes in monoclinic space group P2/c with a=10.174(1) Å, b=11.817(3) Å, c=18.784(4) Å, β=102.14(1)°, V=2207.8(8) ų. I consists of linear metal–metal chains wrapped by dpa ligands. II and III consist of two-dimensional M^II(O₃PH) inorganic sheets cross-linked by 4,4′-bpy ligands, while IV is formed by Mn[O₂PH(C₆H₅)]₂ sheets cross-linked by 4,4′-bpy ligands. I exhibits two-step thermal decomposition at ~200 and ~250°C, resulting in the reduction of Ag⁺ to Ag metal. II loses its coordination water at ~100°C, leaving vacant coordination sites at Co²⁺ ions, while the original framework remains intact. The removal of 4,4′-bpy in II–IV occurs at elevated temperatures above 250, 200 and 400°C respectively.     

Synthesis and sonocatalytic property of rod-shape Sr(OH)2·8H2O

A novel rod-shape sonocatalyst Sr(OH)₂·8H₂O was prepared by a facile precipitation method, and characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and UV–vis absorption spectroscopy. Comparative sonocatalytic degradation experiments were carried out in different conditions under ultrasonic irradiation by using rhodamine B (RhB) as the model substrate, indicating that Sr(OH)₂·8H₂O was highly sonocatalytic. Total organic carbon experiment demonstrated Sr(OH)₂·8H₂O with mass mineralization of organic carbon. The effects of catalyst amount, initial RhB concentration and ultrasonic energy of degradation were investigated, and the sonocatalyst could be reused 5 times without significant loss of activity. Furthermore, the potent degrading capability was ascribed to ultrasonic cavitation producing flash light/energy which generated radicals (e.g., OH) with high oxidation activity.     

Effect of (H2O)n (n = 1–3) clusters on H2O2 + HO → HO2 + H2O reaction in tropospheric conditions: competition between one-step and stepwise routes

ABSTRACT

Effects of (H₂O)_n (n?=?1–3) on the H₂O₂?+?HO?→?HO₂?+?H₂O reaction have been investigated by the reactions of H₂O₂L(H₂O)_n (n?=?1–3)?+?HO and H₂O₂?+?HOL(H₂O)_n (n?=?1–3) at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level of theory, coupled with rate constant calculations by using canonical variational transition state theory. Interestingly, for the former reactions, one-step process and stepwise mechanism are involved, where one-step processes occurring though cage-like hydrogen bonding network complexes and the transition states are favourable. Due to larger effective rate constants, these favourable processes are also favourable than the corresponding latter reactions. Meanwhile, the catalytic effect of (H₂O)_n (n?=?1–3) is mainly taken from water monomer, because the effective rate constant (k'(R_WM2)) of H₂O₂···H₂O?+?HO reaction is, respectively, larger by 3, 6–10 orders of magnitude than that of H₂O₂···(H₂O)₂?+?HO (k'(R_WD1)) and H₂O₂···(H₂O)₃?+?HO (k'(R_WT1)) reactions. Furthermore, the enhancement factor of water molecular (k'(R_WM2)/k_tot) is only 0.28% at 240?K, while at high temperature (such as at 425?K), the positive water vapour effect enhances up to 27.13%. This shows that at high temperatures the positive water effect is obvious under atmospheric conditions.     

Ferromagnetic Interaction between Copper and Terbium Ions in Pentanuclear Cluster [Cu3Tb2(ClCH2COO)12(H2O)8] · 2H2O

For the first time the exchange interaction between copper and non-Kramers Tb³⁺ ions was studied by means of electron paramagnetic resonance (EPR). Features of the manifestation of this interaction in the EPR spectra of dimer fragments Cu–Tb and pentanuclear fragments Cu–Tb–Cu–Tb–Cu are analyzed. The possibility to determine the sign and value of this interaction from EPR spectra for the case when the lowest states of Tb³⁺ are the states |0〉, | ± 1〉 is shown. The exchange interaction between copper and trivalent terbium ions in the studied pentanuclear complex is ferromagnetic. Authors' address: Violeta K. Voronkova, Kazan Physical-Technical Institute, Russian Academy of Sciences, Sibirsky trakt 10/7, Kazan 420029, Russian Federation     

混配配合物[Co(cpida)(C7H5N2)2]·C7H5N2·5H2O

在溶液中用N-(邻苯甲酸基)-亚氨基二乙酸、苯并咪唑和Co(Ac)2·4H2O进行自组装合成了标题三元金属混配配合物.用元素分析、红外光谱、单晶衍射对配合物的组成和结构进行了表征,确定配体N-(邻苯甲酸基)-亚氨基二乙酸中的3个羧基为单齿形式与中心金属钴离子配位.     

The structural transformation of monoclinic [(R)-C5H14N2][Cu(SO4)2(H2O)4]·2H2O into orthorhombic [(R)-C5H14N2]2[Cu(H2O)6](SO4)3: crystal structures and thermal behavior

Single crystals of [(R)-C₅H₁₄N₂][Cu(SO₄)₂(H₂O)₄]·2H₂O (1) were grown through the slow evaporation of a solution containing H₂SO₄, (R)-C₅H₁₂N₂ and CuSO₄·5H₂O. These crystals spontaneously transform to [(R)-C₅H₁₄N₂]₂[Cu(H₂O)₆](SO₄)₃ (2) over the course of four days at room temperature. The same single crystal on the same mounting was used for the determination of the structure of (1) and the unit cell determination of (2). A second single crystal of the transformed batch has served for the structural determination of (2). Compound 1 crystallizes in the noncentrosymmetric space group P2₁ (No. 4) and consists of trimeric [Cu(SO₄)₂(H₂O)₄]^2? anions, [(R)-C₅H₁₄N₂]²⁺ cations and occluded water molecules. Compound 2 crystallizes in P2₁2₁2 (No. 18) and contains [Cu(H₂O)₆]²⁺ cations, [SO₄]^2? anions and occluded water molecules. The thermal decompositions of compounds 1 and 2 were studied by thermogravimetric analyses and temperature-dependent X-ray diffraction.     

水分子(H_2O)中O—H键的稳定性

以水分子(H_2O)双振子二次量子化哈密顿量作为理论模型,通过加横向扰动研究H_2O中氢氧(O—H)耦合量子态的稳定性。结果表明:当水分子中的两个振子能量集中于其中之一时,不易受横向扰动的影响,稳定性好;当振子能量不对称时,极易受横向扰动的影响,稳定性迅速衰减、变差;当两振子振动强度一致时,不易受弱横向扰动的影响,对于比较强的横向扰动稳定性演化曲线呈现近周期性变化,说明该状态在强扰动下极易发生可逆性的跃迁。     

糖精钴水合物[Co(C7H4NO3S)2(H2O)4]·2H2O的合成及晶体结构

以糖精钠(sac-Na)、丙氨酸和硝酸钴为原料合成得到糖精钴琥珀色块状晶体,采用红外、X射线单晶衍射对配合物进行了表征,该晶体属单斜晶系,空间群为P21/c,晶胞参数为:a=0.79269(5)nm,b=1.61407(10)nm,c=0.77026 (5) nm,α=90°,β=99.695(7)°,Ⅴ=0.97145 (11) nm3,Z=2,Dc=1.817g/cm3,F(000)=546,R=0.0278.结构分析表明,中心Co离子与4个O原子和两个N原子配位,处于四角双锥八面体配位环境中,4个水分子在赤道平面上与Co离子配位,晶胞中还包含有2个游离的结晶水,形成了含6个水分子的结晶物.     

E.P.R. study of γ-irradiated single crystals of K2C2O4.H2O and (NH4)2C2O4.H2O

The electron paramagnetic resonance of γ-irradiated single crystals of K₂C₂O₄.H₂O and (NH₄)₂C₂O₄.H₂O has been studied. The spectra show interesting microwave power saturation effects. The singlet spectrum is attributed to the C₂O₄ ^- radical derived from the C₂O₄ ^-- ion. The principal g-values are determined to be 1·998, 2·0028 and 2·0004. Certain weak lines are observed with different power saturation and interpreted as due to OH radicals derived from water molecules in the crystal lattice.     

Adsorption of CO and H2 on Pt(110)(1 × 2) studied by photoemission of adsorbed xenon (PAX)

The adsorption of hydrogen and carbon monoxide on Pt(110)(1 × 2) at 97 K has been studied by photoemission of adsorbed xenon (PAX). For both species, it appears that adsorption takes place first in the valleys between the microfacets of this reconstructed surface. Only when these sites are saturated, does adsorption take place on other sites (microfacets or ridges) of the surface.     

RE(Ala)4(Im)(ClO4)3*2H2O固体配合物的合成及其红外光谱研究

本文通过稀土高氯酸盐与L-丙氨酸(L-Ala)及咪唑(Im)反应,合成了标题配合物RE(Ala)_4(Im)(ClO_4)_3·2H_2O(RE=Pr,Nd,Sm),测定了配合物的红外光谱,对其主要吸收带进行了归属。红外光谱的研究结果表明,丙氨酸以内盐的形式存在于配合物中,通过羧基与稀土离子配位,且随着RE原子量的增大,羧基与RE~(3 )间配位键离子性逐渐减弱,共价性逐渐增大;咪唑环上的N参与了配位。     

Analysis of the interactions in FCCF:(H2O) and FCCF:(H2O)2 complexes through the study of their indirect spin–spin coupling constants

A theoretical study of FCCF:(H₂O)_n complexes, with n?=?1 and 2, has been carried out by means of ab initio computational methods. Three kinds of interactions are observed in the complexes: H···π and H···F hydrogen bonds and O···FC tetrel bonds. The indirect spin–spin coupling constants have been calculated at the CCSD/aug-cc-pVTZ-J computational level. Special attention has been paid to the dependence of the different intramolecular coupling constants in FCCF on the distance between the coupled nuclei and the presence or absence of water molecules. The exceptional sensitivity shown by these coupling constants to the presence of water molecules is quite notorious and can provide information on the bonding structure of the molecule.     

Na0.15(H3O)0.2CoO2·wH2O的超导电性

最近发现的水合钴氧化物超导体在某些方面具有与高温超导体十分相似的性质.本文报道含有高浓度的水合氢离子的钴氧化物超导体的超导电性磁测量结果.通过对样品的M(H,T)的测量,得到了大致的H～T相图.最后还讨论了系统中可能存在的2D～3D转变.