Key Word Index-Kinetic study of some schiff base formation.

No abstract

A conductometric titration technique has been used to investigate the electron transfer activity of CT molecular complexes formed by arylazopyrimidine and naphthylazopyrimidine derivatives as donors and the organic p-acceptors p-nitroaniline, p-chloroaniline, p-bromoaniline, anthraquinone, picric acid, anitroso-b-naphthol, p-hydroxybenzaldehyde and maleic anhydride. The study was performed at different degree of temperature and in three different polar solvents namely N,N-dimethylformamide (DMF), acetonitrile (ACN) and dimethylsulfoxide (DMSO). The stoichiometric ratios of these complexes were found to be 1:1. The dissociation constant (as M ) values of the formed complexes have been calculated, and the effects of solvents as well as types of electron donors on their conductance s p -values have been examined.

Coordination compounds formed by the interaction of some salicylidene aromatic Schiff bases with Y(III), Ce(III), La(III), and Zr(IV) are prepared and characterized by elemental analysis, electronic and i.r. spectra as well as conductometric methods. The i.r. spectra indicate that coordination takes place through the azomethine nitrogen atoms and OH groups. The structure of such products depend mainly on the type of Schiff base used. Also, the formation constant of the complexes are evaluated.

Kinetics of hydrolysis of some bifunctional Schiff bases, bis(x‐benzylidenes)‐o‐phenylenediamine, have been investigated in aqueous media containing 0.1 mole fraction of ethanol under base and acid conditions. Under base conditions the rate determining step is the hydroxide ion attack on the protonated substrate while under weak acid conditions the attack of water rather than hydroxide ion on the protonated substrate becomes the predominant reaction pathway. The bifunctional Schiff base molecular structure‐base or acid hydrolysis reactivity relationship has been examined and discussed. Effect of medium (water content and nature of organic solvents) has been investigated and it is deduced that specific solute‐solvent interactions, namely the proton‐solvent, play a vital role on such hydrolysis reaction.