Perturbations of the fully resolved electronic spectra of large molecules by the internal rotation of attached methyl groups. Influence of complex formation
Tm. Korter et Dw. Pratt, Perturbations of the fully resolved electronic spectra of large molecules by the internal rotation of attached methyl groups. Influence of complex formation, J PHYS CH B, 105(18), 2001, pp. 4010-4017
Rotationally resolved S-1<--S-0 fluorescence excitation spectra of three me
thylindoles and their single atom van der Waals complexes with argon have b
een obtained. Each spectrum is extensively perturbed by the hindered intern
al rotation of the methyl group. Analyses of these perturbations show that
the barriers to such motion are substantially increased by complex formatio
n. Barriers of this type are primarily electronic in origin. Thus, even at
the relatively large distances (3.5 Angstrom) found in van der Waals comple
xes, the attachment of a weakly bound argon atom has a significant effect o
n the electron distribution in the indole ring.