Estimation of ground and excited state dipole moments of quinidine and quinidine dication: Experimental and numerical methods

Abstract

Absorption and fluorescence spectra of quinidine (QD) and quinidine dication (QD2 +) have been measured at room temperature in solvents of different polarities. Ground and excited state electric dipole moments are determined experimentally using solvatochromic shift method based on bulk solvent properties. Numerical calculations are also performed using B3LYP/6-31G(D) level of theory for ground state and CIS/6-31G(D) level of theory for first excited singlet state. From both experimental and numerical studies it has been observed that dipole moment values of excited states (μe) are higher than corresponding ground state value (μg), of QD and QD2 +, which is attributed to the higher polarity of excited states of QD and QD2 + molecules.