نتایج جستجو برای: tetraaza schiff base

تعداد نتایج: 260981  

Journal: :The Journal of biological chemistry 2004
Jay M Janz David L Farrens

Little is known about the molecular mechanism of Schiff base hydrolysis in rhodopsin. We report here our investigation into this process focusing on the role of amino acids involved in a hydrogen bond network around the retinal Schiff base. We find conservative mutations in this network (T94I, E113Q, S186A, E181Q, Y192F, and Y268F) increase the activation energy (E(a)) and abolish the concave A...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1986
M Sheves A Albeck N Friedman M Ottolenghi

Artificial bacteriorhodopsin pigments based on synthetic retinal analogues carrying an electron-withdrawing CF3 substituent group were prepared. The effects of CF3 on the spectra, photocycles, and Schiff base pKa values of the pigments were analyzed. A reduction of 5 units in the pKa of the Schiff base is observed when the CF3 substituent is located at the C-13 polyene position, in the vicinity...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2011
gholamreza karimipour morteza montazerozohori nasrin haghighat naeini

in this study, bis(salicylaldehyde)-4-methyl-1,2-phenylenediimine (bsmp) as a schiff base ligand of n2o2-type and its mn and fe complex as m-bsmp catalyst were synthesized and characterized by uv-vis, ir spectroscopy and elemental analysis. the efficiency of fe- and mn-bsmp catalysts was evaluated in the oxidative decarboxylation of arylacetic acids with tetra-butylammonium periodate (n-bu4nio4...

2015
Asmaa A. Ibrahim

Schiffbase was obtained by condensation of camphor with 4-amino-phenol .The charge transfer complex of the Schiff base as a donor molecule with picric acid as acceptor molecule in methanol were estimated. Schiff-base compound and charge transfer complex were identified by elemental analysis, infrared spectra and UV-visible spectra.The physical parameters of the CT complex were calculated by app...

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The mercury (II) complex, Hg (Meca2en)I2 (1), containing bidentate Schiff base ligand  Meca2en = N,N′-bis[(E)-2-benzylidenepropylidene]ethane-1,2-diamine, has been synthesized and characterized by elemental analyses (CHN) and 1H-NMR spectroscopy. The crystal structure of 1 was determined using single-crystal X-ray diffraction. Structural investigation shows that 1 crystallizes in a monoclinic s...

2017
Minako Oshima Minoru Matsuno Tomoyuki Haraguchi Takashiro Akitsu

We have prepared supramolecular systems of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes and colloidal gold nanoparticles (AuNP) of 10 nm diameters. They demonstrated that direct adsorption of chiral Schiff base metal complex on the surface of AuNP owing to observation of clear induced CD spectra for the first time. We observed and discussed induced CD bands on AuNP from chiral Schiff bas...

2008
Hapipah M. Ali Mohamed Ibrahim Mohamed Mustafa Mohd. Razali Rizal Seik Weng Ng

In the mononuclear complex mol-ecule of the title compond, [ZnCl(2)(C(18)H(18)N(2)O)(2)]·2C(18)H(18)N(2)O, the Zn atom, which lies on a twofold rotation axis, is coordinated by phenolate O atoms in a tetra-hedral coordination geometry. The coordinated Schiff base uses its indole NH donor site to form a hydrogen bond to the negatively charged phenolate O atom of the uncoordinated zwitterionic Sc...

2015
Ali Athar Farmanullah Khan Wasim Ahmed Zakir Khan

Metal complexes of Cu (II), Co (II), Ni (II) and Zn (II) of Schiff based derived from 5-bromo-2hydroxybenzaldehyde and 4-nitobenzenesulfonamide have been prepared and characterized on the basis of physical characteristics, micro-analytical data, H NMR, FTIR spectrum and electronic data. The spectrum data 1 exhibit coordination of Schiff base with metal through imine nitrogen and oxygen atom and...

2014
N. Srividhya

The new Schiff bases are synthesis from various and aldehyde and amine under magnetic stirrer method .The synthesized Schiff base were characterized by spectral techniques (UV-Spectra & IR-Spectra). And the Schiff base are yellow colour solid and having sharp melting point and insoluble in organic solvents.

2002
ROBERT H. ZAUGG JOSEPH A. WALDER

Normal and sickle erythrocytes were exposed in vitro to millimolar concentrations of 31 different carbonyl compounds. Schiff base (imine) linkages were formed with amino groups of intracellular hemoglobin. Adducts were isolated by gel electrofocusing and could be dissociated by dialysis. Aromatic aldehydes proved more reactive than aliphatic aldehydes, and ketones were unreactive. The influence...

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