The formation constants (log K), of the complexes formed between a number of amino acids(glycine , L-valine and L-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °C) in aqueous solutions and at natural pH of p-sulphonato-calix [4] arene (pH=3.2) bymeans of UV-Vis spectrophotometeric technique have been investigated. At this pH the guestmolecule is in its cat...

the equilibrium constant of adduct formation between some triorganotin chloride of the type r3sncl (r=c6h5, p-ch3c6h4, n-ch3)ch2)3, c6h5-ch2 and lewis bases cl¯, br¯, and i¯, were measured in 50% v/v ethanol-water solvent spectrophotometrically. the average equilibrium constant values for the systems studied shows the following acceptor trend of tin(iv) in the triorganotin chlorides: p-tolyl > ...

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...

  Abstract: In this work, the kinetics of ethane hydrate formation has been studied experimentally and a kinetic model based on chemical affinity has been described for predicting the hydrate growth process in the stirred batch reactor at a constant volume. The experiments were done with both pure water and aqueous solution of sodium dodecyl sulfate (SDS). The effect of SDS on formation kineti...

In this study, alkaline colloidal silica was prepared by titration of an alkaline solution such as sodium silicate with silicic acid in constant range of pH  .This constant range of pH was achieved by using concentrated soduim silicate solutions as pH adjusting solutions during titration.The sodium silicate solutions  having a variety of...

the kinetics of catalyst deactivation and coke formation during dehydrogenation of propane over supported pt–based catalysts and, in particular, the effect of alkali metal promoters on catalyst activity and stability were studied. the analysis of propane conversion data showed that there is an optimum level of alkali metal promoter loading for both catalyst activity and stability.a model based ...

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...