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1.
The stability constants of binary complexes of Zn(Ⅱ)-α-amino acid and ternary complexes of Zn(Ⅱ)-N-Salicylideneaminio acid (ligand A)-α-amino acid(ligand B) at (25±0.1)℃ and in the presence of 0.1 mol·L-1 KNO3 have been determined by pH method. The α-amino acid(Aa) used were Glycine(Gly), L-Serine(Ser), L-Leucine(Leu), L-Proline(Pro) and L-Phenylalanine(Phe). It was found that the linear free energy relationship (LFER) exists nicely between the following parameter pairs logβ102 and pKB2, logβ111 and pKB2, and logβ111 and pKA2. The ΔlgK was used to characterize the stability of ternary complexes related to the stability of parent binary complexes. The hydrophobic interaction between ligands in the ternary complexes was studied.  相似文献   

2.
王燕  刘光祥  王宁  沈应中 《无机化学学报》2008,24(10):1729-1732
A transition metal complex Zn(mpc)2(H2O)2 (Hmpc=3-methylpyrazole-5-carboxylic acid) has been synth-esized by the reaction of Hmpc with Zn(NO3)2·6H2O using hydrothermal method, which was characterized by IR spe-ctra, elemental analysis and single-crystal X-ray structure analysis. The structure reveals that the complex crystallizes in the trigonal space group R3c with the Zn atom on a threefold axis, composed of one Zn atom, two independent mpc- ligands and two coordinated water. Hydrogen bonds link the molecules into a three-dimensional supramolecular architecture. Fluorescent analysis in the dilute EtOH solution shows that the title complex exhibits a broad fluorescent band at 471 nm upon photoexcitation at 280 nm and has a bathochromic shift of the emission energy compared with the free ligand, possibly due to metal-to-ligand charge transfer (MLCT). CCDC: 682402.  相似文献   

3.
The geometric configurations of binuclear Zinc(Ⅱ) complex Zn2[(n-Bu)2NCSS]4 and the ligand Na[(n-Bu)2 NCSS] have been optimized by B3LYP quantum chemical method. The electronic structures have been performed by density functional theory at B3LYP/6-31G* level. The electronic spectrums of the complex and ligand were calculated by ZINDO/S-CIS method. It is indicated from the calculation that: (1) The coordination effect of bridging ligand is bigger than that of chelating one, and the bridging ligands also translate more charge to Zn than the chelating one. (2) The calculated results about electronic spectrums are similarly to experimental measurement, and farther explain that absorption band at λ=267 nm of complex is assigned to two n → π* transitions :one arising from the bridging ligands and the another mainly arising from the chelating ligands;but absorption band at λ=236 nm of complex is assigned to π → π* transition which the electron mainly translates from the bridging ligands to the chelating ligands. (3) By consideration of delocalization and polar effects in coordination, the charge transfer from ligand to metal decreases the π-π and p-π conjugation effects in the chromophore group NCS2 and to increase the energy needed for the π → π* and n → π* transitions, and results in the absorption bands shifting towards the short wavelength direction.  相似文献   

4.
5-Chloro-2-methoxybenzoates of heavy lanthanides and yttrium were obtained as di- or tetrahydrates with a metal to ligand ratio of 1:3 and general formula: Ln(C8H6ClO3)3nH2O, where n=2 for Ln=Tb, Dy, Y and n=4 for Ln=Ho, Er, Tm, Yb, Lu. The complexes were characterized by elemental analysis, IR and FIR spectra, thermogravimetric studies, X-ray diffraction and magnetic measurements. The carboxylate group appears to be a symmetrical, bidentate, chelating ligand. All complexes are polycrystalline compounds. Their thermal stabilities were determined in air and in nitrogen atmospheres. When heated they dehydrate to form anhydrous salts which next in air are decomposed to the oxides of the respective metals while in nitrogen to the mixtures of carbon and oxides or carbon and oxychlorides of respective metals. The complexes are more stable in air than in nitrogen. The solubilities of yttrium and heavy lanthanide 5-chloro-2-methoxybenzoates in water at 293 K are of the order of 10–3 mol dm–3 The magnetic moments of the complexes were determined over the range 77–298 K. They obey the Curie–Weiss law. The values of μeff calculated for all compounds are close to those obtained for Ln3+ by Hund and Van Vleck. The results indicate that there is no influence of the ligand field of 4f electrons on lanthanide ions and the metal ligand bonding is mainly electrostatic in nature. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

5.
手性配体立体选择性萃取分离扁桃酸对映体   总被引:6,自引:0,他引:6  
Based on chiral ligand exchange, the distribution behavior of mandelic acid enantiomers in the two-phase system containing copper ion(Ⅱ)(Cu2+) and N-n-dedecane-L-hydroxyproline (L), was studied. At different pH, the partition of Cu2+ in the two-phase system containing N-n-dedecane-L-hydroxyproline, was investigated. The formation constant of binary cpmplex(Li2Cu) was obtained by regression. The influence of pH, concentrations of Cu2+ and chiral ligand, and solvents on partition coefficients(K) and separation factor(α), was discussed. The experimental results show that Li forms more stable ternary complex with D-mandelic acid than with L- mandelic acid. There is a large influence of pH on K and α. At low pH values (<3.5), formation of binary complexes is thermodynamically unfavourable. K and α are best when pH values are above 3.5 and the molar ratio of chiral ligand to Cu2+ is 2∶1. At the same time, solvents influence K and α very much.  相似文献   

6.
A new binuclear copper (Ⅱ) complex with 1,10-phen and fluoroquinolone ligands, [Cu2(cfc)2(phen)2(pip)](NO3)2(CO)2,was synthesized and its crystal structure was solved.The formula of the complex is C28H24ClCuFN5O7, and the crystallography data are as follows, triclinic, space group P1, a=0.80372(6)nm, b=0.94712 (7)nm, c=1.67826(13)nm, α=88.5650(10)°, β=80.9920(10)°, γ=70.2780(10)°, V=1.18722(6)nm3, Z=2, D=1.848g· cm-3, F(000)=676. R1=0.0627 and wR2=0.1684 (I>2σ(I)). The copper atom is five- coordinate with square-based pyramidal geometry and involves two nitrogen atoms from phen, two oxygen atoms from cfc and one nitrogen atom from pip anion. The stacking effect between cfc and phen ligands from two neighboring molecules was observed. FT-IR spectrum of the complex was also discussed. Both ligand and complex were assayed against gram-positive and gram-negative bacteria by doubling dilutions method; the complex shows the same mini-mal inhibitory concentration (MIC) as the corresponding ligand against S. Aureus, E. Coli and M. Lutens bac-teria. The inhibitory effect of the ligand and complex on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured by using MTT (Methyl-Thiazol- Tetrozolium) and SRB (Sulphurhodamin B) assay meth-ods, respectively. The results indicated that the complex has strong inhibitory effect on HL-60 and BEL-7402 cell line. CCDC: 203964.  相似文献   

7.
A new N,N′-diacetic acid substituted azacrown ether containing thiophere ring ligand(H2L) has been synthesized by using salicylaldehyde, diamine, thiophene and bromoacetic acid as starting materials. With this ligand, its lanthanide complexes [ML(NO3)]·nH2O(M=La,Ce,Pr,Nd,Sm,Eu,Dy,Er,Yb;n=2 or 3) are prepared. These compounds are characterized by elemental analysis, IR, 1H NMR, MS and conductivity measurements. The results show that ether oxygen, carboxy oxygen, nitrogen atoms and nitrate ion are coordinated to the metal ion.  相似文献   

8.
Two new binuclear Fe(Ⅲ)-Fe(Ⅲ) and Mn(Ⅱ)-Mn(Ⅱ) complexes containing the dianions of chloranilic acids (CA) which act as bridging ligand in the complexes, have been synthesized namely [Fe2(phen)4(u-CA)](ClO4)4·2H2O and [Mn2(phen)4(u-CA)](ClO4)2·3H2O (phen = O-phenanthroline; CA = dianions of chloranilic acids). They have been characterized by elemental analyses, IR, electronic spectra, susceptibility and variable-temperature magnetic susceptibility. The results indicate that there is a antiferromagnetic interaction between metal ions in the complexes at low temperature. The observed data were well fitted to those from a Heisenberg model. The obtained parameters: J= -2.02cm-1, g = 2.25 for Fe(Ⅲ)-Fe(Ⅲ) complex; J=-5.45cm-1, g = 2.01 for Mn(Ⅱ)-Mn(Ⅱ) complex.  相似文献   

9.
The complex [Cd(tren)(meim)](ClO4)2 was synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The compound crystallizes in monoclinic system, space group P21/m with a=0.786 8(2) nm, b=0.834 2(2) nm, c=1.496 2(4) nm, Mr=538.64, Z=2, F(000)=542, Dc=1.822 g·cm-3, T=298(2) K, μ=1.435 mm-1 and λ=0.071 073 nm. The structure was refined to R=0.045 8 and wR=0.123 1 for 1 489 observed reflections with I>2σ(I). The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method. It was found to be active against the four test bacterial organisms. CCDC: 600198.  相似文献   

10.
A new binuclear copper(Ⅱ) complex containing fluoroquinolone ligand, [Cu2(cfc)2(bpy)2(pip)]·6H2O, was synthesized and its crystal structure was solved. The formula of the complex is C25H26ClCuFN4O6, and the crystal-lography data are as follows, triclinic, space group P1, a=6.874(2)?, b=10.761(3)?, c=17.976(5)?, α=80.071(6)°, β=85.253(6)°, γ=79.109(6)°, V=1284.5(6)?3, D=1.542g·cm-3F(000)=614, and Z=2. R1=0.0776 and wR2=0.2235(I >2σ(I)). The copper atom is five-coordinate with square-based pyramidal geometry and involves two nitrogen atoms from bpy, two oxygen atoms from cfc and one nitrogen atom from pip anion. The stacking effect between cfc and bpy ligands from two neighboring molecules was observed. Both ligand and complex were assayed against gram-positive and gram-negative bacteria by doubling dilutions method, the complex shows the same minimal inhibitory concentration (MIC) as the corresponding ligand against S.Aureus and E.Coli bacteria. The inhibitory effect of the ligand and complex on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured by using MTT (Methyl-Thiazol- Tetrozolium) and SRB (Sulphurhodamin B) assay methods. The results indicated that the complex has strong inhibitory effect on HL-60 cell line and on BEL-7402 cell line. CCDC: 191087.  相似文献   

11.
γγγ-Trifluorocarbonyl compounds are easily obtained in a good yield by introduction of the 1,1,1-trifluoroethyl moiety (CF3-CH2-) on the -methylene group of a ketone.  相似文献   

12.
Zusammenfassung Mo3CoB3, Mo3NiB3, W3CoB3 und W3NiB3 kristallisieren in einem eigenen Typ (W3CoB3-Struktur). Das trigonal prismatische Bauelement [T 6B]* ist zu Ketten vereinigt, wobei B3-Gruppen entstehen. Die Phasen sind vermutlich Bor-reicher als obiger Formel entspricht.
The crystal structure of W3CoB3 and the isotypic phases Mo3CoB3, Mo3NiB3, and W3NiB3
Mo3CoB3, Mo3NiB3, W3CoB3, and W3NiB3 were found to possess a new type of crystal structure (W3CoB3-structure type). Trigonal prismatic groups [T 6B]* are linked together forming chains in such a way that B3-groups occur. These borides do probably exist with a larger amount of boron as to compared with the formula.


Mit 2 Abbildungen  相似文献   

13.
K3SbSe3, Rb3SbSe3, and Cs3SbSe3 – Synthesis and Crystal Structure The compounds K3SbSe3, Rb3SbSe3 and Cs3SbSe3 were synthesized by heating mixtures of Sb2O3 and an alkalicarbonate in a stream of hydrogen saturated by selenium in a temperature range between 750 °C and 800 °C. The compounds crystallize isostructural with Na3AsS3. A comparison of atomic distances and bond angles with those of the isostructural arsenic and bismuth compounds shows the effect of lone pairs.  相似文献   

14.
γ-Nitro-γ-butyrolactone By oxidation of 3-(1-nitro-2-oxocyclohexyl)propanal ( 1 ) with KMnO4, besides 3-(1′-nitro-2′-oxocyclohexyl)pripionic acid ( 2 ), the complete hydrolysis product 4-oxononanedioic acid ( 4 ) and the oxidized semi-hydrolysis product 5-(2-nitro-5-oxotetrahydro-2-furyl)pentanoic acid ( 3 ) were formed. The crystalline 3 decomposes at r.t. forming 4 and nitrous gases; its structure was established by X-ray determination.  相似文献   

15.
Thin films of methylammonium lead halides, CH3NH3PbI3 and CH3NH3PbI3-xClx, were deposited onto symmetrical microstructured electrode arrays of gold or platinum on Si/SiO2 wafers. Polarization studies were carried out on perovskite films under vacuum in the dark. For poling, a constant voltage was applied to the samples while the temperature was cycled between 295 K and 4 K. The measured current densities depending on the temperature showed distinct characteristics relating strongly to the crystal phase and the dielectric properties of the perovskite films. Voltage sweeps were carried out at different scan rates at specific temperature intervals after poling. The polarization of the films due to the migration of iodide vacancies in direction of the blocking perovskite/metal interface was frozen almost up to room temperature. Charge carriers were only able to cross the blocking barrier and contribute to the current where the ions have accumulated during poling. All J-V curves showed hysteresis: inverted and regular hysteresis at room temperature and below, respectively. Inverted hysteresis originates from the slow accumulation of ions at the blocking barrier, while regular hysteresis arises from a distortion in the adjacent crystals which will be discussed.  相似文献   

16.
K3BiSe3, Rb3BiSe3, and Cs3BiSe3 – Derivatives of the Th3P4 Structure Type The compounds K3BiSe3, Rb3BiSe3, and Cs3BiSe3 were synthesized by heating mixtures of Bi2O3 and the respective alkalicarbonate in a stream of hydrogen saturated by selenium at 850°C. Thin crystals of the compounds appear red in transmitted light. They crystallize isostructural with Na3AsS3, space group P213, lattice constants a = 9.771(5) Å, a = 10.161(3) Å, and a = 10.587(5) Å for K3BiSe3, Rb3BiSe3, and Cs3BiSe3, respectively. The Na3AsS3 structure type is a derivative of the Th3P4 structure type.  相似文献   

17.
The synthesis of derivatives of 3-amino-3-deoxy-L-erythrose by LAH or LAD reduction of the oxime of 1,2-O-isopropylidene α-L -glycero-tetros-3-ulofuranose is described.  相似文献   

18.
Condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groups, in the KOH-DMSO system, was used to prepare previously unknown 1-alkylthio-3H pyrrolizin-3-ones. The latter, treated with secondary amines, are readily converted to the corresponding 1-amino derivatives.  相似文献   

19.
Previously unknown 1-alkylthio-3H-pyrrolizin-3-ones have been obtained by the condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groupings in the KOH-DMSO system. On treating the products with secondary amines they are readily converted into the corresponding 1-amino derivatives.Irkutsk Branch of the Russian Academy of Sciences, Irkutsk 664033. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 919–924, July, 1996. Original article submitted May 2, 1996.  相似文献   

20.
Zusammenfassung Es wurden die Enthalpien der Reaktionen von AsCl3, AsBr3, AsJ3, SbCl3, SbBr3 und SbJ3 mit Tributylphosphat, N,N-Dimethylacetamid und Hexamethylphosphorsäuretriamid bestimmt. Das Verhalten der Addukte bei Gegenwart eines Überschusses der Donoren wird beschrieben.
Acceptor properties of AsCl3, AsBr3, AsI3, SbCl3, SbBr3, and SbI3
The enthalpies of the reactions of AsCl3, AsBr3, AsI3, SbCl3, SbBr3 and SbI3 with tributylphosphate, N,N-dimethylacetamide and hexamethylphosphoric acid triamide were measured. The behavior of the adducts in the presence of excess donor molecules is described.


Mit 5 Abbildungen  相似文献   

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