摘要:

AbstractThe self‐assembly of NiCl2·6H2O with a diaminodiamide ligand 4,8‐diazaundecanediamide (L‐2,3,2) gave a [Ni(C9H20N4O2)(Cl)(H2O)] Cl·2H2O (1). The structure of1was characterized by single‐crystal X‐ray diffraction analysis. Structural data for1indicate that the Ni(II) is coordinated to two tertiary N atoms, two O atoms, one water and one chloride in a distorted octahedral geometry. Crystal data for1:orthorhombic, space groupP21nb, a= 9.5796(3) Å,b= 12.3463(4) Å,c= 14.6305(5) Å, Z = 4. Through NH···Cl–Ni (H···Cl 2.42 Å, N···Cl 3.24 Å, NH···Cl 158°) and OH···Cl–Ni contacts (H···Cl 2.36 Å, O···Cl 3.08 Å, OH···Cl 143°), each cationic moiety [Ni(C9H20N4O2) (Cl)(H2O)]+in1is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thermogrametric analysis of compound1is consistent with the crystallographic observations. The electronic absorption spectrum of Ni(L‐2,3,2)2+in aqueous solution shows four absorption bands, which are assigned to the3A2g→3T2g,3T2g→1Eg,3T2g→3T1g, and3A2g→3T1gtransitions of triplet‐ground state, distorted octahedral nickel(II) complex. The cyclic volammetric measurement shows that Ni

ISSN:0009-4536    

DOI:10.1002/jccs.200700197

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractDerivatives of 5,7‐dichloro‐2‐styrylquinoline (1), modified at position 8 of quinoline moiety with a methyl ether (4, DCSQM) or acetate (5, DCSQA), were synthesized and investigated. Both compounds exhibited high thermal stability (Td>320 °C). The UV‐vis absorption of DCSQM and DCSQA varied only slightly in different solvents, whereas the emission spectra showed pronounced red shifts with increasing solvent polarity, suggesting the intramolecular charge transfer character of the emission state. Compounds4and5can emit lights from blue to green color in different solvents. The solvent polarity dependent electronic transitions are attributed to efficient intramolecular charge transfer (ICT) processes, in which the HOMOs and LUMOs are localized on the styrene‐based ring and the quinoline‐based moiety, respectively. The quinoline‐based LUMO provides compelling evidence that the first reduction site occurs on the electron‐deficient

ISSN:0009-4536    

DOI:10.1002/jccs.200700198

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractA very simple spectrophotometric method for simultaneous determination of aluminum(III) and iron(III) based on formation of their complexes with pyrocatechol violet (PCV) in micellar media, using the H‐point standard addition method (HPSAM), is described. In micellar media, the metal complexes of Al‐PCV and Fe‐PCV are formed very fast. Formation of both of the complexes was complete within 5 min at pH 8.5. The linear ranges for aluminum and iron were 0.05‐2.50 and 0.10‐4.00 μg mL−1, respectively. The relative standard deviation (R.S.D.) for the simultaneous determination 0.40 μg mL−1of Al(III) and 0.20 μg mL−1of Fe(III) were 3.24% and 4.22%, respectively. Interference effects of common anions and cations were studied. The method was applied to simultaneous determination of Al(III) and Fe(III) in standard reference material

ISSN:0009-4536    

DOI:10.1002/jccs.200700199

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractRecycling of sugarcane bagasse and its coal as metal sorbents to capture metal ions from wastewater is the aim of this study. Thus, stability of sugarcane bagasse and its coal, in addition to the solubilities of metal ions in synthetic solution, were determined in this study at different pH values. Also, sorption of Fe, Mn, Cd, and Pb ions with different concentrations (10‐100 mg L−1) on different grain size fractions of sugarcane bagasse (μm) and its coal (Mn in the case of coal. Generally, the results of this study suggest that the sugarcane bagasse and its coal might provide an economical method for the remov

ISSN:0009-4536    

DOI:10.1002/jccs.200700200

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractA simple, rapid, cost effective and extraction‐free spectrophotometric method has been developed for the determination of zolmitriptan in pharmaceutical raw and dosage forms. The method is based on the charge‐transfer reaction of zolmitriptan in acetonitrile medium with 0.2% 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone to form a colored product peaking at 555 nm. Beer's law is obeyed in the concentration range 10‐250 μg mL−1with molar absorptivity of 1.7 × 103L mole−1cm−1. The effects of variables such as reagent concentration, time of reaction, color stability and interferences have been investigated to optimize the procedure. The results have been validated analytically and statistically. The proposed method has been successfully applied for the determination of zolmitriptan in pharmaceutical formulations. Results indicate that the method is accurate, precise and reproducible (relative

ISSN:0009-4536    

DOI:10.1002/jccs.200700201

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractA simple and sensitive spectrophotometric method has been developed for the determination of the antihypertensive drug captopril and anticancer drug 6‐mercaptopurine, in their trithiocarbonate (TTC) form by using Pd(II) chloride as a coloring reagent. Captopril TTC forms a stable dark yellow colored complex with λmax383 nm, molar absorption coefficient 1.35 × 105l/mole/cm and a Beer's law range from 0.084‐1.26 ppm. 6‐Mercaptopurine TTC forms a stable deep yellow colored complex with λmax345 nm, molar absorption coefficient 6.9 × 105l/mole/cm and a Beer's law range from 0.0319 ppm to 3.519 ppm. The M: L ratio of palladium: TTC complexes were confirmed by Job's method of continuous variance and mole ratio method and was found to be 1:1 for both captopril TTC as well as 6‐mercaptopurine TTC. In addition, on the basis of, FTIR,1H NMR, ESR and thermal analysis data a plausible structure of mononuclear Pd(II) complex of Captopril TTC and 6‐mercaptopurine TTC has

ISSN:0009-4536    

DOI:10.1002/jccs.200700202

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractThree galactose‐specific lectins have been isolated and purified from the extract of pumpkin seed kernels by gel filtration on Sephadex G‐75 with 100% ammonium sulfate saturated crude extract, followed by ion exchange chromatography on DEAE‐cellulose and affinity chromatography on Sepharose 4B. All three lectins were found to be homogeneous as judged by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE). The molecular weights of lectins, PSL‐1, PSL‐2 and PSL‐3, as estimated by gel filtration on Sephadex G‐75 were 40,000, 42,000 and 46,000, and by SDS‐PAGE about 39,500, 41,000 and 45,000, respectively. The lectins, PSL‐1, PSL‐2&PSL‐3 were dimer in nature and the molecular weights of their subunits were about 25,500 and 14,000; 26,000 and 15,000; and 30,500 and 15,000, respectively. The lectins are glycoproteins with a neutral sugar content of 3‐5%. The lectins agglutinated rat red blood cells and the hemagglutination was inhibited specifically by galactose and galactose‐containing saccharides. The lectins exhibited a strong cytotoxic effect in a brin

ISSN:0009-4536    

DOI:10.1002/jccs.200700203

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractThe formation of carbon tetrachloride‐benzene charge transfer complex was confirmed by UV and NMR spectrometric studies. A change in UV spectrum of benzene is observed upon addition of carbon tetrachloride. Whereas the appearance of new bands supports the formation of charge transfer complex. NMR study shows that, chemical shift of benzene pmr signal depends on the CCl4‐C6H6molar ratio. This observation is another criterion for the formation of benzene‐carbon tetrachloride charge transfer complex. Job's Continuous Variation method indicates that a 2:1 CCl4‐C6H6charge transfer complex (2:1 CTC) is formed. The association constants (K2:1) of (2:1 CTC) was found to be 0.0197 M−2. The maximum concentration of (2:1 CTC) was found to be in samples with 2:1 CCl4‐C6H6molar ratio (33% benzene mole). On the other hand the maximum yield of chlorobenzene was obtained, also, upon radiolysis of CCl4‐C6H6samples at a 2:1 molar ratio (33% benzene mole). Therefore, it could be concluded that (2:1 CTC) participates in the formation of chlorobenzene upon radiolysis of the benzene‐carbon tetrachloride system. This conclusion was supported by the dependence of the chlorobenzene yield of a γ‐irradiated carbon tetrachloride‐benzene system (2:1 molar ratio) on irradiation time according to a third order kinetic equation with a very good linearity (R2= 0.9977). Accordingly, the rate constant for the chlorobenzene formation under this condition was found to be ≈ 5.5 × 10−7L2.mol−2.h−1. We propose a radiation chemical mechanism in which the 2:1 CTC plays a role in t

ISSN:0009-4536    

DOI:10.1002/jccs.200700204

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractThe density functional method was applied to the study of 1,1‐diamino‐2,2‐dinitroethylene (Fox‐7)/H2O dimer. All the possible dimers (1, 2and3), as well as the monomers, were fully optimized with the DFT method at the B3LYP/6‐311++G**level. The basis set superposition errors (BSSE) are 4.62, 4.07 and 3.45 kJ/mol, and the zero point energy (ZPE) corrections for the interaction energies are 7.94, 5.66 and 6.40 kJ/mol for1, 2and3, respectively. Dimer1is the most stable, judged by binding energy. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of dimer1was predicted to be −29.36 kJ/mol. The charge redistribution mainly occurs on the adjacent N–H··· O atoms and N–O··· H atoms between submolecules. The oxygen in the nitro group acts as a moderate hydrogen acceptor as compared to water oxygen. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities (C0P), entropies (S0T) and thermal corrections to enthalpy (H0T), and the changes of thermodynamic properties on going from monomer to dimer over the temperature range 200.00‐700.00 K were predicted. It is energetically or thermodynamically favorable for Fox‐7 to bind with H2O and to form

ISSN:0009-4536    

DOI:10.1002/jccs.200700205

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY

摘要:

AbstractThe dielectric behaviour of 1,2‐propanediol was investigated to understand the effect of the hydroxyl group on the dielectric parameters. The measurement of permittivity ϵî and ϵîî of 1,2‐propanediol was carried out in the frequency range 10 MHz to 20 GHz at 25 °C temperature. Static permittivity and dielectric relaxation time are extracted from a 1,2‐propanediol‐water mixture using the bilinear calibration method and non‐linear least squares fit method. Calculated Kirkwood correlation factor contains information regarding solute‐solvent interaction. The hydrogen bonded model suggested by Luzar is applied to determine the molecular parameters. The excess dielectric parameters and Bruggeman factor show the systematic change in the dielectric parameter of the system with change

ISSN:0009-4536    

DOI:10.1002/jccs.200700206

出版商:WILEY‐VCH Verlag    

年代:2007

数据来源: WILEY