| Infrared spectroscopy was employed to measure the carbonylstretching vibrational frequencies (υ（C=O）) of MedroxyprogesteroneAcetate（MPA） and Megestrol Acetate（MA） in single solvent and binarysolvent systems. The frequencies of absorption bands were studied toinvestigate the solvent-solute interactions between MPA and MA indifferent solvents.In binary solvent systems, the binary solvents were composed ofCCl4/cyclo-C6H12,CHCl3/cyclo-C6H12,C2H5OH/cyclo-C6H12,iso-C3H7OH/cyclo-C6H12. The studies of regularity of υ（C=O）of solutes in binary solventmixtures according to the effects of solvent-composition changes were usedto disscuss the solvent-solute interaction mechanism and the representation.The results showed that in CCl4/cyclo-C6H12binary solvents, MPAmolecular could form1:1hydrogen bonding with CCl4while MA wereonly affected by the dipolarityï¼polarizability; in CHCl3/cyclo-C6H12 binary solvents, both MPA and MA were formed1:1hydrogen bondingwith CHCl3; in C2H5OH/cyclo-C6H12and iso-C3H7OH/cyclo-C6H12binarysolvent systems, the solutes also formed1:3hydrogen bonding withacohols.In this work, the the carbonyl stretching vibrations of MPA and MA(υ（C=O）) were also measured in different kinds of single solvents. Therelationships between the υ（C=O）of solutes and the solvent polarity empiricalparameters included single empirical parameters and multiparameterapproaches and the applicability of these solvent polarity empiricalparameter equations were investigated. The single empirical parameterswere the solvent accepter number （AN）, Brownstein’s parameter S value,Dimroth and Reichart’sparameter ET（30）, Schleyer’s linear free energyequation （G-value）. And the Swain parameters （Ajand Bj） and the linearsolvation energy relationships（LSER） were included as the multi-parameterapproaches. The results showed that the correlation between the υ（C=O）andG-value was the better, the next was the one between the υ（C=O）and S valueand AN-value, but The one between the υ（C=O）and ET（30） was notsignificant. Besides, the correlations between the υ（C=O）and the twomulti-parameter equations.The solvent effect of phthalide and chloroform was initially studiedusing a density functional theory （DFT） method at theBecke3LYP/6-31+G（d） level and SCRF （self consistent reaction field） model. The results showed that some properties of phthalide such asconfiguration, Mulliken atomic charges, energy and so on were influencedby solvent effects. Moreover, a strong hydrogen bonding formed betweenphthalide and chloroform was spontaneously happened in the chloroformsolvent. The calculated vibrational frequencies in different phases are ingood agreement with the experimental values. |
PDF Full Text Request