Rotationally resolved electronic spectroscopy in the gas phase, in the absence and presence of an applied electric field, has been used to distinguish the two conformers of 3-aminophenol (3AP) on the basis of differences in their electric dipole moments. cis-3AP has μ = 2.3 D, and trans-3AP has μ = 0.7 D, in their ground electronic states. The two observed values are approximately equal to those expected on the basis of bond dipole additivity rules. However, these rules fail to predict the large change in both the magnitude and the orientation of μ when the two conformers of 3AP absorb light. cis-3AP has μ = 3.3 D, and trans-3AP has μ = 1.7 D, in their excited S1 electronic states; the angles of orientation of μ with respect to the a inertial axis change by 13° and 38°, respectively. This effect is attributed to 1Lb/1La state mixing in the S1 state.
ASJC Scopus subject areas
- Colloid and Surface Chemistry