THERMODINAMIC PROPERTIES OF LACTAMS OVER THE INTERVAL 298-1500 K
According to the experimental data and quantum chemical calculations B3LYP/6-311++G (3df, 3pd), B3LYP/aug-cc-pVQZ and MP2/6-311++G (3df, 3pd) within the model «rigid rotator—anharmonic oscillator» the enthalpy of formation, entropy, free energy and heat capacity of cyclic lactams with the cycle grade n = 4÷8 over the interval 298-1500 K were found. Conformational analysis was performed. For all the structures the harmonic frequencies were calculated. Anharmonic frequencies were obtained for the global minima of each compound within the vibrational second-order perturbation theory in the quartic force field with B3LYP/6-311++G (3df, 3pd).