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31.
The design, synthesis and coordination of a novel multisite vic-dioxime compound, LH2, containing flexible pyridine substituents and aminophenylsulfanyl moieties on the periphery, facilitating solubility in water as pyridinium hydrochloride salt are described. LH2 was prepared by the reaction between 2-(2-pyridylethylamino)-benzenethiol and (E,E)-dichloroglydioxime. Mononuclear [(E,E)M] (M=NiII, CuII, CoII, FeII and MnII) and dinuclear uranyl (UO2
II) complexes of LH2 were isolated and characterized with metal:ligand ratios of 1:2 and 2:2, respectively. The reaction of Na2PdCl4·3H2O and AgNO3 in DMF with the mononuclear complex, (LH)2Ni, resulted in the formation of the heterotrinuclear complexes [Pd2Ni(LH)2]Cl4 and [Ag2Ni(LH)2](NO3)2. The complexes were characterized by elemental analysis, 1H-n.m.r., u.v.--vis. spectroscopy, i.r., and MS (LSIMS). The redox properties of the complexes were studied by cyclic voltammetry. 相似文献
32.
Atıf Koca Musa Şahin Ahmet Gül Rabia Z. Uslu 《Monatshefte für Chemie / Chemical Monthly》2002,133(8):1135-1145
Summary. In this study, the electrochemical properties of metal-free and nickel-containing porphyrazines with eight tosylaminoethylthia
groups were investigated using cyclic voltammetry, double potential step chronoamperometry, double potential step chronocoulometry,
and controlled potential coulometry. Cyclic voltammetry measurements showed that both compounds exhibit two quasi-reversible and an irreversible reduction waves. The first electron transfer reaction was followed by an irreversible chemical
reaction, the second one by a reversible chemical reaction for both species. The electrode processes of metal-free and nickel-containing
porphyrazines are diffusion controlled, but the double potential step chronocoulometry measurements indicated that the nickel
porphyrazine is adsorbed at the electrode. However, a small adsorption current has no significant effect on the mass transport
mechanism of the system. Diffusion coefficients of both compounds were determined by both cyclic voltammetric and chronocoulometric
measurements. The diffusion coefficients of the reduced forms of the porphyrazines were found to be smaller than those of
the neutral forms.
Received October 29, 2001. Accepted (revised) December 17, 2001 相似文献
33.
Summary. In this study, the electrochemical properties of novel porphyrazines with eight crown ether substituents appending on the
periphery through flexible chains were investigated by using cyclic voltammetry and controlled potential coulometry. Cyclic
voltammetry measurements showed that the metal free porphyrazine gave all of the six possible redox reactions of common porphyrazine
derivatives. Cobalt porphyrazine exhibited a metal-based reduction and a metal-based oxidation processes followed by two ligand-based
reduction and two oxidation processes. I
p vs. ν1/2 plots of redox processes of the two compounds indicated the diffusional mass transfer mechanism of the complexes. Copper
porphyrazine gave an oxidation process having adsorption properties and three reduction reactions. The variations of peak
current ratios of electrochemical reactions for all three complexes with scan rate showed that electron transfer processes
of complexes were followed by reversible or irreversible chemical reactions. Aggregation and sandwich adduct formation properties
of complexes were determined by CV measurements. Peak potentials of redox processes for all complexes were shifted towards
positive potentials by addition of alkali metal cations. Addition of K+ formed sandwich type adducts with 15-crown-macrocycles diminishing aggregation of planar molecules by intramolecular rather
than intermolecular complexation.
Corresponding author. E-mail: ahmetg@itu.edu.tr
Received May 23, 2002; accepted (revised) May 31, 2002 相似文献
34.
Rabia Zeynep Uslu Kobak Duygu Akyüz Atıf Koca 《Journal of Solid State Electrochemistry》2016,20(5):1311-1321
Metallophthalocyanines (MPcs) (M = 2H+, Zn2+, Co2+, and Cu2+) bearing diethylaminophenoxy and chloro substituents at the peripheral positions (MPc-tdea-tCl) were coated on the working electrodes with the electropolymerization and tested as electrochromic materials. Altering the metal center of MPcs affected the redox activities of MPc-tdea-tCl films. All electropolymerized MPc-tdea-tCl films behaved as conductive and redox active films in different electrolyte systems. Electrochromic properties of MPc-tdea-tCl films were investigated via the voltammetric, in situ spectroelectrochemical, and in situ spectroelectrocolorimetric measurements. H 2 Pc-tdea-tCl film did not give any electrochromic response, while ZnPc-tdea-tCl and CuPc-tdea-tCl films behave as a reasonable electrochromic material. Distinctive color changes with short response times, high optical contrast, and better optical and coulombic stabilities were only observed with CoPc-tdea-tCl film. 相似文献
35.
Adam J Kríz Z Prokop MP Wimmerová M Koca J 《Journal of chemical information and modeling》2008,48(11):2234-2242
This article is focused on the application of two types of docking software, AutoDock and DOCK. It is aimed at studying the interactions of a calcium-dependent bacterial lectin PA-IIL (from Pseudomonas aeruginosa) and its in silico mutants with saccharide ligands. The effect of different partial charges assigned to the calcium ions was tested and evaluated in terms of the best agreement with the crystal structure. The results of DOCK were further optimized by molecular dynamics and rescored using AMBER. For both software, the agreement of the docked structures and the provided binding energies were evaluated in terms of prediction accuracy. This was carried out by comparing the computed results to the crystal structures and experimentally determined binding energies, respectively. The performance of both docking software applied on a studied problem was evaluated as well. The molecular docking methods proved efficient in identifying the correct binding modes in terms of geometry and partially also in predicting the preference changes caused by mutation. Obtaining a reasonable in silico method for the prediction of lectin-saccharide interactions may be possible in the future. 相似文献
36.
R.?Ko?Email author M.?Koca G.??ahino?lu 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,48(4):583-586
The most general one dimensional reaction-diffusion
model with nearest-neighbor interactions solvable through the
empty interval method, and without any restriction on the
particle-generation from two adjacent empty sites is studied. It
is shown that turning on the reactions which generate particles
from two adjacent empty sites, results in a gap in the spectrum of
the evolution operator (or equivalently a finite relaxation time). 相似文献
37.
α- and β-substituted tetrakis(6-hydroxyhexylthiol) phthalocyaninato manganese (III) chloride complexes have been prepared via cyclotetramerization. Both complexes have been characterized by elemental analysis, FTIR, MS and UV–Vis spectral data. The voltammetric and in situ spectroelectrochemical studies reveal that both complexes exhibit an oxidation and three reduction processes having reversible, one-electron, and diffusion controlled mass transfer characteristics, which are assigned to MnIIIPc2−/MnIVPc2−, MnIIIPc2−/MnIIPc2−, MnIIPc2−/MnIPc2−, and MnIPc2−/MnIPc3− couples respectively. The existence of oxygen in solution significantly affects the in situ spectroelectrochemical behavior of the complexes due to the formation of μ-oxo MnPc species. An in situ electrocolorimetric method has been applied to investigate the colors of the electro-generated anionic and cationic forms of the complexes for the first time in this study. The complexes, coated on a glassy carbon electrode potentiostatically, show considerable high electrocatalytic activity to hydrogen evolution reactions in aqueous solution. 相似文献
38.
39.
Synthesis and Structural Characterization of Pyrrole Heterocyclic Systems Bearing Amino Acid Units: Novel Pyrrol‐3‐ones,Pyrrolo[1,2‐a][3,1]benzoxazines,and Pyrrolo[2,1‐b][1,3]oxazoles 下载免费PDF全文
İrfan Koca Mustafa Saçmacı Filiz Yılmaz Şevket Hakan Üngören 《Journal of heterocyclic chemistry》2014,51(1):212-218
Furan‐3‐one derivatives 1 were converted into 2‐hydroxy‐pyrrole‐3‐ones 4 by reacting with various α‐ and β‐amino acids. In contrast, the reaction of furan‐3‐ones and 1‐aminocyclobutanecarboxylic acid afforded spiro‐pyrrolo[2,1‐b][1,3]oxazoles 5 via the pyrrole‐3‐one intermediate under the same reaction conditions. Some of 2‐hydroxy‐pyrrole‐3‐ones 3 derived from anthranilic acids were transformed to pyrrolo[1,2‐a][3,1]benzoxazines via intramolecular esterification. 相似文献
40.
Zülfiye lter Cengiz Soykan Murat Koca 《Journal of polymer science. Part A, Polymer chemistry》2003,41(19):2996-3005