Ab initio simulation of pyrene spectra in water matrices

Abstract

The absorption and emission spectra of free pyrene and pyrene in a water ice matrix were simulated ab initio with their vibronic profiles. Water ice was mimicked by a large cluster of explicit water molecules.

Vibronic structure of electronic absorption and fluorescence spectra of pyrene in the complex with β-cyclodextrin in the presence of nonpolar and polar solvents

“…Accord ing to calculations, the first band corresponds to the 0-0 S 0 → S 2 transition in the electronic absorption spectrum of pyrene, and the shoulder and the second band correspond to vibronic satellites with Δν ~ 420 and 1500 cm -1 [11]. Previously [3] bands at 29673.6 and 31055.9 cm -1 were observed in the absorption spectrum of pyrene in water; the positions of these bands are in agreement with our data.…”

“…Although organic molecule-cyclodextrin insertion complexes are formed in aqueous solutions [11], it was found impossible to obtain direct evidence for the for mation of the Py@2βCD complex, e.g., by the PMR method [5c] because the micromole concentration of complexes controlled by the concentration of pyrene, which is poorly soluble in water, precludes the use of this method. Therefore, the main evidence for the insertion of the substrate into the cyclodextrin cavity was an increase in intensity and a change in the vibronic structure of fluorescence.…”

Calculation of vibrationally resolved absorption spectra of acenes and pyrene

“…The vibrational bands originate mainly from the coupling with the bond stretching and skewing modes in the molecular plane as illustrated for pyrene in ref. 64. The vibrational bands in the absorption spectrum are assigned in Table 3.…”

Thymine based copolymers: feasible sensors for the detection of persistent organic pollutants in water

“…48 Several examples described in the literature have shown that specic solute-solvent non-covalent interactions should be considered as one of the various aspects of uorescence phenomenon. 49,50 The random copolymeric synthesis used in this work yields statistical water soluble copolymers, with several potential conformational changes that could explain the distortion observed. 51 This important point deserves further discussion since dissimilar non-covalent interactions in different samples can lead to dramatic changes in the uorescence spectra, which could hinder achieving the set goal.…”