mobile carrier properties of two schiff base ligands, named bis(2-hydroxypropiophenone)-1,2-propanediimine (n2o2) and bis(1'-hydroxy-2'-acetonaphthone)-2,2'-diiminodiethylamine (n3o2), dissolved in dichloromethane for the extraction of copper(ii) ions from an ammonium buffer feed phase into a nitric acid solution (receiving phase) were investigated and compared. the parameters influencing the t...

An N(4) tetradentate [1 + 1] Schiff base metal free macrocycle HL was prepared, by 1 : 1 condensation of 2,2'-iminobisbenzaldehyde (1) and diethylenetriamine, and characterised. Seven mononuclear complexes, [Zn(II)L(py)](BF(4)) (2), [Cu(II)L](BF(4))]·H(2)O (3), [Ni(II)L](BF(4))·H(2)O (4), [Co(II)L](BF(4))]·H(2)O (5), Fe(III)L(BF(4))(2)·2H(2)O·MeCN (6), [Co(III)L(NCS)(2)]·0.3py (7) and [Fe(III)L...

The application of an external electric field to dry films of Asp-85-->Asn mutant bacteriorhodopsin causes deprotonation of the Schiff base, resulting in a shift of the optical absorption maximum from 600 nm to 400 nm. This is in marked contrast to the case of wild-type bacteriorhodopsin films, in which electric fields produce a red-shifted product whose optical properties are similar to those ...

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...

Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SR...

the vo(iv) complexes of tridentate ono schiff base ligands derived from 2- aminobenzoicacid and salicylaldehyde derivatives were synthesized and characterized by ir, uv–vis and elemental analysis. electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. a good linear correlation was observed between the oxidation potentials and the electron-withdrawing charac...

some new symmetrical tetraaza schiff base ligands containing 2-quinolinecarboxaldehyde moiety formed from condensation reaction of 2-quinolinecarboxaldehyde and o-phenylenediamine derivatives, such as n, nˊ-bis(2-quinolylmethylidene)-4-methoxy-1, 2-phenylenediimine (l1), n, nˊ-bis(2-quinolylmethylidene)-4-methy-1, 2-phenylenediimine (l2), n, nˊ-bis(2-quinolylmethylidene)-4-chloro-1, 2-phenylene...

addition of potassium cyanide to a mixture of schiff base and lithium perchlorate afforded a-aminonitriles in high yields. addition of potassium cyanide to a methanolic solution of schiff base and phosphoric acid afforded a-aminonitriles. when the reaction mixture was refluxed it gave a-amino acids in high yields.