the formation of charge-transfer complexation between dibenzo-15-crown-5 (db15c5) and benzo-12-crown-4 (b12c4) (donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (dcm) and 1,2-dichloroethane (dce) solution at 25°c. the change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. values of formation cons...

in this study the binding abilities of 1,3-calix[4]biscrown-6 (l) toward ba2+ and ca2+ have beenestablished in methanol by spectrophotometric measurements at 25±0.1 °c and 0.01 m ionicstrength, and with using specfit computer program; stability constants for 2 : 1, metal : ligandcomplexes has been estimated

The effect of SDS (0.03-0.07 M) and Brij-35(0-0.003 M) concentrations and temperature on retention parameters of 30 solutes in micellar reversed- phase liquid chromatography systems were studied using solvation parameter model. The system constants were determined by multiple linear regression analysis from experimental values of the retention factors with known descriptors by computer usin...

roasting has considerable effects on the quality of cream made of nuts. in this study, the roasting conditions of walnut kernels were optimized based on the stability parameters of the produced cream. temperatures of 100-150°c for 10-30 minutes were used to roast walnut kernels. the amount of oil separation, peroxide, acidity and thiobarbituric acid values of the cream, as well as color paramet...

Catalyst S. Al-Khattaf* Chemical Engineering Department, King Fahd University of Petroleum & Minerals Dhahran 31261, Saudi Arabia Abstract Catalytic transformation of toluene has been investigated over Y-zeolite based catalysts in a novel riser simulator at different operating conditions. A number of experiments were carried out in the temperature range of 400-500C to understand the transformat...