The 7-hydroxyquinoline-water complexes,7-HQ-(H2O)n(n=1,2),have been studied by the density functional theory at the B3LYP/6-311G level,with counterpoise correction.The optimized geometric parameters and interaction energies for various complexes were estimated.The most stable hydrogen bond complex of 7-HQ-(H2O)1 involved a six-membered ring made up of two hydrogen bond O-H.O and C-H.O.The most stable hydrogen bond complex of 7-HQ-(H2O)2 had two six-membered rings made up of four hydrogen bonds and another four-membered ring.Hydrogen bond interaction energies were found to be 26.32 and 65.07kJ/mol for the most stable 7-HQ-(H2O)1 and 7-HQ-(H2O)2 respectively,indicating that relatively strong hydrogen bonds may be formed in both systems.
According to the theoretical bases of thermokinetics and analog thermogram method, a general analog thermogram method for several types of reversible reactions, with which the rate constants of forward and backward reactions and equilibrium constant can be calculted from the same thermogram simultaneously, has been proposed in this paper. The thermokinetics of the reactions of nitroethane with ammonia at 15℃ and 25℃ and with tris (hydroxymethyl)aminomethane at 15℃ and 30℃ have been studied with this method,re-spectively. The results of rate constants and equilibrium constants calculated with this method are in agreement with those in literatures. Therefore, the analog thermogram method for the reversible reactions is believed to be correct.
