Subject: Physical Chemistry · Chapter: Molecular Spectroscopy · Topic: Raman · Exam: NET JUNE 2017 · Marks: 2 · Difficulty: Medium
The first electronic absorption band maximum of a polar and relatively rigid aromatic molecule appears at 310 nm but its fluorescence maximum in acetonitrile solution appears with a large Stokes shift at 450 nm . The most likely reason for the Stokes shift is
(a)Large change in molecular geometry in the excited state
(b)Increase in dipole moment of the molecule in the excited state
(c)Decrease in polarizability of the molecule in the excited state