Solvent Effect on the Vibrational Structures of the Fluorescence and Absorption Spectra of Pyrene

Abstract

The anomalously large Ham effect observed in pyrene has been studied in various solvents at room temperature by measuring the fluorescence and absorption spectra. As in the case of benzene, the Ham bands of pyrene were assigned to the 0–0 and ag-vibration bands. This was confirmed by fluorescence polarization measurement. The correlation of the intensities of the fluorescence and absorption bands to solvent polarities is discussed.

In Situ Probing of Oxygen-Containing Groups on Acid-treated Carbon Nanofibers using Aromatic Molecules

“…The fluorescence peaks at 372, 382, and 392 nm observed at day 0 are assigned to pyrene present in liquid phase of the suspension. The intensity of the 0−0 vibronic bands is significantly enhanced at the expense of other bands in the polar solvents due to solute−solvent dipole−dipole interaction (Nakajima, 1971;Kalyanasundaram & Thomas, 1977). The relative peak intensity at 372 nm to that at 382 nm decreased with the ultrasonic irradiation time in both the N-CNF and AA-CNF systems, and the spectrum became a feature similar to that observed in non-polar solvent such as cyclohexane.…”

“…It is well known that the ratio of vibronic peak intensities in fluorescence spectra of pyrene changes with the surrounding polarity (Nakajima, 1971;Kalyanasundaram & Thomas, 1977). Therefore, pyrene is available to use as an in-situ probe of polarity in the surrounding media.…”

Growth and characterization of pyrene crystals on carbon nanofibers

“…The fluorescence spectrum of Supernatant A excited at 335 nm exhibits a dual fluorescence. One is the vibronic bands seen at 372-392 nm and is assigned to the pyrene monomer in water [26,32,33]. The other is the broad band, which has a peak at 460 nm, due to an excimer-like fluorescence, as observed in the spectrum at the 360 nm excitation.…”

Untitled

“…The band ratio I 1 /I 5 was studied as a function of trum [19]. Due to this effect, the vibrational bands in the different solvent polarity parameters: dipole moment, pyrene molecule that are forbidden in weak electronic dielectric constant, Kosower parameter, and Dimroth parameter.…”