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1.
利用水热法成功合成了一个新颖的稀土-过渡金属有机骨架Er(pyba)3(H2O)2CuI(Hpyba=4-吡啶-3-苯甲酸),并通过元素分析、红外光谱、X-射线粉末衍射、单晶X-射线衍射及热分析等对其进行了表征。结构分析表明:2种不同的{Er2}和{Cu2}单元经配体连接形成一维链,这些一维链通过氢键和π-π堆积作用进一步连接形成三维超分子网络。  相似文献   

2.
Prior to this study no data for the solubility product of BiPO4(cr) or the complexation constants of Bi with phosphate were available. The solubility of BiPO4(cr) was studied at 23±2?°C from both the over- and under-saturation directions as functions of a wide range in time (6–309 days), pH values (0–15), and phosphate concentrations (reaching as high as 1.0 mol?kg?1). HCl or NaOH were used to obtain a range in pH values. Steady state concentrations and equilibrium were reached in <6 days. The data were interpreted using the SIT model. These extensive data provided a solubility product value for BiPO4(cr) and an upper limit value for the formation of BiPO4(aq). Because the aqueous system in this study involved relatively high concentrations of chloride, reliable values for the complexation constants of Bi with chloride were required to accurately interpret the solubility data. Therefore as a part of this investigation, existing Bi–Cl data were critically reviewed and used to obtain values of equilibrium constants for various Bi–Cl complexes at zero ionic strength along with the values for various SIT ion interaction parameters. Predictions based on these thermodynamic quantities agreed closely with our experimental data, the chloride concentrations of which ranged as high as 0.7 mol?kg?1. The study showed that BiPO4(cr) is stable at pH values <9.0. At pH values >9.0, Bi(OH)3(am) is the solubility controlling phase. Reliable values for the Bi(OH)3(am) solubility reactions involving Bi(OH)3(aq) and $\mathrm{Bi}(\mathrm{OH})_{4}^{-}$ and the formation constants of these aqueous species are also reported.  相似文献   

3.
Dark red transparent crystals of [Co{1,4-C(6)H(4)(CN)(2)}(2){NTf(2)}(2)][SnI{Co(CO)(4)}(3)](2) are obtained by reacting SnI(4), Co(2)(CO)(8) and 1,4-C(6)H(4)(CN)(2) in the ionic liquid [EMIm][NTf(2)] (EMIm: 1-ethyl-3-methylimidazolium; NTf(2): bis(trifluoromethylsulfonyl)imide). According to X-ray structure analysis based on single crystals, the title compound crystallizes in a triclinic manner and contains the novel (2)(∞)[Co{1,4-C(6)H(4)(CN)(2)}(2){NTf(2)}(2)] coordination network. This infinite 2D network is composed of Co(2+) ions that are planarily interlinked by four 1,4-dicyanobenzene ligands. As a non-charged 2D network, Co(2+) is furthermore coordinated by two [NTf(2)](-) anions. The (2)(∞)[Co{1,4-C(6)H(4)(CN)(2)}(2){NTf(2)}(2)] layers are stacked on top of each other with SnI[Co(CO)(4)](3) molecules intercalated in distorted cubic gaps between the layers. The title compound is furthermore characterized by energy dispersive X-ray (EDX) analysis, thermogravimetry (TG), infrared spectroscopy (FT-IR) and optical spectroscopy (UV-Vis).  相似文献   

4.
In order to obtain a clue to the antitumor mechanism of $\left[ {{\text{Me}}_{ 3} {\text{NH}}} \right]_{ 6} \left[ {{\text{H}}_{ 2} {\text{Mo}}_{ 1 2}^{\text{V}} {\text{O}}_{ 2 8} \left( {\text{OH}} \right)_{ 1 2} \left( {{\text{Mo}}^{\text{VI}} {\text{O}}_{ 3} } \right)_{ 4} } \right]$ ·2H2O (PM-17), the interaction of PM-17 with flavin mononucleotide (FMN) as a prosthetic group of the flavoprotein has been investigated by both polarographic analysis and isothermal titration calorimetry (ITC) technique at the physiological solution pH (7.5). The half-wave potential (?0.50 V vs. Ag/AgCl) of the d.c. polarogram for the quasi-reversible one-electron reduction of FMN was shifted by PM-17 toward a more positive potential with a resultant deviation from one-electron reduction to formally more than one-electron reduction waves. The PM-17 effect on the d.c. polarogram could be explained by a variety of FMN···(PM-17)n (n > 0) aggregates with multiple conformations which was supported by the thermodynamic parameters (ΔH = ?29.7 kJ mol?1, ΔS = ?28.2 J mol?1 K?1, ΔG = ?21.5 kJ mol?1, and number of FMN in the binding with PM-17 (N) = 0.053 at 20 °C) estimated by the ITC technique. A large conformational change of the FMN domain by the FMN···(PM-17)n aggregates is suggested to prevent the movement of the FMN centers into close proximity with nicotinamide adenine dinucleotide (NADH) with a resultant depression of the electron transport in NADH dehydrogenase.  相似文献   

5.
成分为MoFeS_(10)Cl_4N_4C_(34)H_(54)的单晶样品,用SYNTEX-R3型四圆衍射仪以θ/2θ扫描方式收集3499个独立的X射线衍射强度数据进行结构分析。晶体属空间群C_s~4—C_c,晶胞参数a=17.900(5),b=18.466(7),c=15.483(4),β=92.78(2)°,Z=4,经PL,K,B及吸收因子的校正得绝对强度,由Patterson函数先导出Mo参数,随后用Fourier法有层次地导出S,Fe,Cl,N,C等非氢原子的坐标参数,另由直接法亦导出大部分非氢原子的位置,所得结果是平行的。用块矩阵最小二乘法对坐标及各向同性与各向异性的热参数进行多轮的修正,最后加入全部氢原子,同时进行氢原子各向同性热参数的修正,得一致性因子R=0.054,结构分析证实:晶体中存在有三类物种,四个二乙胺基硫代甲酸根与Mo(Ⅴ)组成了{Mo[S_2CN(C_2H_5)_2]_4}~(=1)络离子,它与负络离子{FeCl_4}~(-1)交替排列构成了沿c轴方向伸展的空腔,而电中性的苄基二硫化物,则充填其间组成了结构新颖的三元体系包合物。  相似文献   

6.
We report the electrochemical and chemical synthesis of the first isolable iron carbonyls obtained directly from an {Fe4S4}-cluster and carbon monoxide: the structure of one product of chemical reduction, [Fe3S(CO)9]2−, had been determined by X-ray crystallography.  相似文献   

7.
本文报道了用MoCl_5,Fecl_3,二乙胺基硫代甲酸钠和苄基硫醇试剂,在甲醇溶液中合成了一种新型的三元包合物。并对此包合物进行了元素分析、X光结构测定、红外光谱、紫外可见光谱、电子顺磁共振谱、差热-热重分析以及磁性测定。这种晶体十分稳定,又包含多种键型,是一种罕见的三元包合物。  相似文献   

8.
我们合成了化合物{Mo[S_2CN(C_2H_5)_2]_4}~ {MoCl_6}~-,确定了其所属晶系、空间群及晶胞参数,并确定了重原子与其它全部非氢原子坐标等.  相似文献   

9.
The solvation of Buckminsterfullerene \(\hbox {C}_{60}\) by para-hydrogen and ortho-deuterium clusters has been modeled using a dedicated potential and path-integral molecular dynamics simulations at low temperature (2 K). The solvation shell obtained from the distribution of radial distances is found to be complete near 50 molecules, in agreement with recent mass spectrometry measurements. Deuteration increases the shell size by one, indicating a denser shell owing to less prominent vibrational delocalization for this heavier isotope.  相似文献   

10.
通过水热合成的方法,以1,4-环己烷二羧酸、2,4-二氨基-6-甲基三嗪和CdCl_2·2.5H_2O为原料合成了一种单核的化合物{Cd(dmt)_2(Hchdc)_2(H_2O)_2}_n(dmt=2,4-diamino-6-methyl-triazine,H2chdc=1,4-cyclohexanedicarboxylic acid),并进行了IR和X射线单晶衍射(常温)的分析.结果表明,该化合物属于P2/c空间群,单斜晶系,晶胞参数:a=1.330 26(11)nm,b=0.541 47(4)nm,c=2.415 54(16)nm,β=115.751(3)°,V=1.567 1(2)nm~3,Z=2,Dc=1.570g/cm~3,F(000)=764,R1=0.035 2,wR2=0.092 7.该化合物中,中心金属离子Cd(II)与氧相连形成六配位构型,并通过4种不同的氢键作用最终形成了三维的堆积结构.  相似文献   

11.
The redox characteristics of the ternary clathrate compound{C6H5CH2SSCH2C6H5}was studied by electrochemical measurement and quantum-chemical calculations.The cyclic voltammogram of this ternary clathrate compound in 0.1M KC1O4-DMF with a platinum electride had 2.pairs of redox peak.Both the electrochemical parameters derived from the voltammogram and the results of EHMO calculations indicate that the pair of redox peak at relatively positive potentials corresponds to the redox reaction of "Fe(Ⅲ)/Fe(Ⅱ) which is irreversible in nature,while the pair of redox peak at more negative potentials corresponds to the redox reaction of Mo(Ⅴ)/ Mo(Ⅱ) which is semi-reversible.The calculations from experiment measurements are fairly agreement with the theoretical calculations.  相似文献   

12.
The reaction of [Sb(2)W(22)O(74)(OH)(2)](12-) and [Fe(4)(H(2)O)(10)(β-TeW(9)O(33))(2)](4-) with (NH(4))(2)[RuCl(6)] in aqueous solution resulted in the novel ruthenium(IV)-containing polyanions [{Ru(IV)(4)O(6)(H(2)O)(9)}(2)Sb(2)W(20)O(68)(OH)(2)](4-) and [{Ru(IV)(4)O(6)(H(2)O)(9)}(2){Fe(H(2)O)(2)}(2){β-TeW(9)O(33)}(2)H](-), exhibiting two cationic, adamantane-like, tetraruthenium(IV) units {Ru(4)O(6)(H(2)O)(9)}(4+) bound to the respective polyanion in an external, highly accessible fashion.  相似文献   

13.
The title compound, [{Na(H2O)3}2{Ru(dmso)3}2(MoO4)3]·3H2O, has been obstructure was determined by single-crystal X-ray diffraction method. The crystal crystallizes in the triclinic system, space group P1 with a = 12.3333(3), b = 12.6289(3), c = 32.0284(14)(A), α =79.873(7), β = 87.549(9), y = 64.500(4)°, V = 4429.5(2) (A)3, Z = 4, Mr = 1358.85, Dc = 2.038g/cm3, F(000) = 2696 and μ = 1.874 mm-1. The compound contains a novel pentanuclear triangle bipyramidal core, [{ Ru(dmso)3 } 2(MoO4)3]2-, which consists of two { Ru(dmso)3 } 2+ fragments and three {μ2-MoO4}2- units. Furthermore, the dmso ligands bridge the pentanuclear [Ru2Mo3] core and two [Na(H2O)3]+ fragments together, forming a neutral heptanuclear ruthenium- and sodiumcontaining polyoxomolybdate.  相似文献   

14.
Three structurally different metallasiloxanes were formed from reactions between in situ generated suspensions of Ph2Si(OH)2/BuLi (1∶2) in tetrahydrofuran (THF) with, metal dichlorides MgCl2·2THF, CrCl2, or CoCl2 followed by toluene/Py (Py=pyridine) work-up. The X-ray structures are reported for: [Mg{O(Ph2SiO)2}2]-μ-(LiPy)-μ-{(LiPy)3(OH)(Cl)] (1) incorporating two six-membered magnesiasiloxane rings and an MgLi3O3Cl cubane fragment, [{O(Ph2SiO)2}Co{O(Ph2SiO)3}-μ-(LiPy2)2] (2) with both six-and eight-membered cobaltasiloxane rings and [Cr{O(Ph2SiO)2}2-μ-(LiPy2)2] (3) with two six-membered chromiasiloxane rings. Structure assembly in these cases is apparently dictated by the metal dichloride. The compound [{O(Ph2SiO)2}Mg{O(Ph2SiO)3}-μ-(CoClPy)2]·Py (4) is formed from [{O(Ph2SiO)2}Mg{O(Ph2SiO)3}-μ-(LiPy2)2] and CoCl2 (1∶2).  相似文献   

15.
A high-nuclearity polyoxopalladate compound, [Pd(II)(2)?{H(7)Pd(II)(15)O(10)(PO(4))(10)}](9-) {Pd(II)(17)}, comprising a {Pd(15)} host occupied by a {Pd(2)} guest and the parent pristine "empty" [H(7)Pd(II)(15)O(10)(P(V)O(4))(10)](13-) {Pd(15)} cluster have both been prepared and characterized by single-crystal X-ray crystallography, (31)P NMR, CSI-MS, and XPS. The encapsulated {Pd(2)} has a short Pd(II)-Pd(II) distance within the {Pd(15)} host. Solution studies indicate that the empty host and filled guest complex are in equilibrium with each other, and UV titrations revealed a binding constant of ca. 10(3) for the guest Pd(II) ions, with a binding stoichiometry of almost 2.  相似文献   

16.
The title compound {Cu2(pdc)2(4,4′-bipy)(H2O)(3H2O}2 1 (H2pdc = pyridine-2,6- dicarboxylic acid, also known as dipicolinic acid; 4,4′-bipy = 4,4′-bipyridine) has been synthesized by the hydrothermal reaction and its structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pī with a = 7.2278(3), b = 10.6259(4), c = 17.7614(6)A, α= 79.5990(10), β = 83.6300(10), γ = 71.8280(10)o, V = 1272.60(8)A3, C48H44Cu4N8O24, Mr = 1371.07, Z = 1, Dc = 1.789 g/cm3, μ = 1.747 mm-1, F(000) = 696, R = 0.0397 and wR = 0.1137 for 3938 observed reflections (I > 2σ(I)). There are two kinds of Cu coordination environments, and each central copper(II) atom is five-coordinated in a distorted square-based pyramidal coordination geo- metry. Four copper(II) atoms are linked by four pdc and two 4,4′-bipy ligands to form an annular rectangle structure. Extensive hydrogen-bonding interactions involving carboxylate O atoms as well as coordinated and free water molecules lead to the formation of a three-dimensional network struc- ture.  相似文献   

17.
Exposing a Au{111} surface to NO(2) and then to CO at temperatures around 120 K in ultra-high vacuum gives rise to molecular overlayers in which the two species are co-adsorbed, which we have investigated using low-temperature scanning tunnelling microscopy. Under NO(2)-rich conditions, a (√7 × √7)R19.1° phase with 3:1 NO(2):CO stoichiometry forms. Under CO-rich conditions, this phase co-exists with other phases having 2:1 and 1:1 NO(2):CO stoichiometries and different symmetries, and with bare Au surface. Structural models for these phases are discussed. Individual domains of the (√7 × √7)R19.1° phase are chiral, by virtue of the arrangement of their achiral components, an observation that may have more general implications.  相似文献   

18.
《Chemical physics letters》1999,291(1-2):145-149
The distortion away from the C2v symmetry observed in the X-ray structure of the {p-But-calix[4]-(OMe)2(O)2ZrCl2} complex is explained with the help of density functional calculations on the Zr(OH)2(H2O)2Cl2 model system. The distortion is not caused by intermolecular packing effects but rather by the steric constraints imposed upon the O–Zr–O bond angles by the attachment of the oxygen atoms to the calix[4]arene ligand.  相似文献   

19.
The crystal structure of di(-Ophenoxy)-bis{nitrato-2-[2-(hydroxyethylimino)-methyl]-phenoloimid-azolecopper} was determined. The crystals are monoclinic: a = 10.222(2) Å, b = 13.810(3) Å, c = 10.620(2) Å, =103.67(3)°, space group P21/n, Z = 2, R = 0.050. The copper atom coordinates the singly deprotonated 2-[2-(hydroxyethylimino)-methyl]-phenol molecule, imidazole, and nitrate ion. The coordination polyhedron of the central atom is an extended tetragonal bipyramid with imine and imidazole nitrogen atoms and phenol and alcohol oxygen atoms lying in its base. One axial vertex of the bipyramid is occupied by the oxygen atom of the nitrato group and the other vertex, by phenol oxygen atom of the neighboring complex joined with the initial complex by the symmetry center. Two bridging phenol oxygen atoms unite the complexes into a centrosymmetrical dimer.  相似文献   

20.
The study of the metastable states, obtained by thermal quenching or by light irradiation in the [{Co(prm)(2)}(2){Co(H(2)O)(2)}{W(CN)(8)}(2)]·4H(2)O complex, is reported using powder X-ray diffraction, Raman spectroscopy, optical reflectivity, and magnetic measurements. This compound is characterized by a electron-transfer (ET) phase transition occurring between a high-temperature phase (HT phase) formed by paramagnetic Co(II)-W(V) units and a low-temperature phase (LT phase) formed by diamagnetic Co(III)-W(IV) units. Metastable phases can be induced at low temperature either by thermal quenching rapidly cooling phase named RC or by irradiation photo-induced phase named PI similar to the well-known Light-Induced Excited Spin State Trapping effect. The relaxation dynamics of the metastable phases have been studied and revealed some differences between the RC and PI phases. The sigmoidal shape of the relaxation curves in the RC phase is in agreement with the cooperative nature of the process. Thermodynamic parameters that govern the relaxation have been determined and used to reproduce the experimental Thermal-Induced Excited Spin State Trapping curve.  相似文献   

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