Properties Of Azomethines Research Articles

Characterization, optical and thermal properties of new azomethines based on heptadecafluoroundecyloxy benzaldehyde

New thermotropic liquid crystals containing a long alkoxysemiperfluorinated chain (-O-(CH2)3-(CF2)7-CF3), one linking unit in mesogenic cores (HC=N-) and different functional end-groups such as 4-hexadecyl-, 4-n-hexadecyloxy- chain, or biphenyl-4-carbonitrile, 4-diazenyl-N,N-dimethylbenzene or pyren were synthesized via a one-step route. The methods of nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), ultraviolet–visual (UV-vis) and photoluminescence (PL) spectroscopy as well as differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) were used. The absorption (UV-vis) and PL features of all compounds are documented. The amine had an effect on the mesomorphic properties of the azomethines. An enantiotropic smectic phase was observed for all of the systems studied. As a result of DSC and POM investigations, it is shown that liquid crystalline properties of the azomethines exhibit a strong dependence of the end-groups. The mesomorphic behaviour of the compounds was investigated also by FTIR(T) and UV-vis(T) spectroscopy. Current–voltage measurements were performed on an ITO/compound/Alq3/Al device.

Free Radical Production by Azomethine H: Effects on Pancreatic and Hepatic Tissues

The antimalarial properties of azomethine H represent the basis for its use as a chemotherapeutic agent. This work was carried out in order to verify the biological side effects of azomethine H and to clarify the contribution of reactive oxygen species (ROS) in this process. It was shown that azomethine H increased serum activities of amylase, alanine transaminase (ALT) and the TBARS concentrations, in rats. No changes were observed in glutathione peroxidase and catalase activities. The drug-induced tissue damage might be due to superoxide radicals (O2), since Cu-Zn superoxide dis-mutase activities were increased by azomethine H treatment. This study allows tentative conclusions to be drawn regarding which reactive oxygen metabolites play a role in azomethine H activity. We concluded that (O2) maybe produced as a mediator of azomethine H action.

Synthesis and spectral-luminescence properties of azomethines in the coumarin series

Nitration of 7-diethylamino-4-methylcoumarin and reduction of the resulting 3-nitro derivative gave 7-diethylamino-3-amino-4-methylcoumarin. A series of azomethines have been synthesized based on this material. The spectral-luminescence properties of the products have been investigated.

Synthesis and properties of azomethines based on 1-nitrophenyl-2-formylpyrroles

Schiff bases were obtained by the reaction of 1-nitrophenyl-2-formylpyrroles with aromatic amines, and their spectral characteristics were studied.

Synthesis and properties of azomethines of the pyran series

2-Formyl-Δ5-dihydropyran reacts with amines to give azomethines. Δ2-Triazolines are formed in the reaction of azomethines containing aromatic substituents with diazomethane. The structures of the compounds obtained were proved by means of UV and PMR spectroscopy.

Synthesis and certain biological properties of azomethines of quinaldines

Absolute ethanol was used for the condensation of the quinaldine aryl halides with p-nitroso-bis-(/ 3-chloroethyl)aniline in order to avoid hydrolysis of the bis-(chloroethyl )amino group. The obtained azomethines are intensely colored crystalline products readily soluble in the usual organic solvents, poorly soluble in water, and insoluble in benzene and ether. The physicochemical constants are given in Table 1. The dependence of color on the structure of the prepared azomethines agrees with the ideas concern