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ABSTRACT:The polymerization kinetic of methacrylamide with the KMnO 4 /glycine redox system has been investigated volumetrically at 35Ϯ0.1°C under nitrogen atmosphere in aqueous sulfuric acid medium in a dimethylsulfoxide/H 2 O mixture (5% v/v). Ϫ /glycine redox system under mild conditions. The reaction proceeded with radical mechanism and the overall energy of activation (E a ) was calculated to be 29.87 kJ/mol from the Arrhenius plot in the temperature range 25-50°C. Molecular weight of the polymer was determined by viscometry.

ABSTRACT:The effect of some substituents on intramolecular hydrogen bonding of 5-X-2-hydroxybenzaldehyde (5-X-2-HBA) has been studied by B3LYP and MP2 methods using 6-311ϩϩG** and AUG-cc-PVTZ basis sets. The relationship between hydrogen bond energy E HB and electron donation (or withdrawal) of substituents has been investigated. An approximately good linear relationship has been detected between Hammett coefficients and hydrogen bond formation energy (R 2 ϭ 0.98). Herein, population analysis has been performed by atoms in molecules (AIM) and natural bond orbital (NBO) methods. The results of AIM and NBO analyses are in a good agreement with calculated energy values. Furthermore, correlation between ring aromaticity and hydrogen bonding has been investigated by nucleus-independent chemical shift (NICS) at GIAO/B3LYP/6-311ϩϩG** level of theory.

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