A series of 2-(5,6,7,8-tetrahydroimidazo[1,5-a]pyridin-3-yl)phenols with different substituents (R) in the para position with respect to the hydroxyl group, was synthesized. The photophysical properties of these species have been investigated in dichloromethane solution: they displayed intense fluorescence when excited with UV light (310–340 nm), with λmax of emission varying in the range 430–530 nm and lifetime decay of few nanoseconds. A very large Stokes shift (up to 189 nm) and high absolute quantum yields (up to 0.72) were recorded for most of the compounds. Moreover, good tuning of the emission is observed according to the electronic features of the substituent R, and a linear correlation was found between the emission maxima of the compounds and the Hammett σp constants of R. Two of these (tetrahydroimidazo[1,5-a]pyridin-3-yl)phenols were then chosen for preliminary measurements of their photophysical properties when dispersed in a host polymeric matrix (PMMA).

Synthesis and emissive properties of a series of tetrahydro (imidazo[1,5-a]pyrid-3-yl)phenols: A new class of large stokes shift organic dyes

MARCHESI, ARIANNA;Stefano Brenna∗
;
G. Attilio Ardizzoia
2018-01-01

Abstract

A series of 2-(5,6,7,8-tetrahydroimidazo[1,5-a]pyridin-3-yl)phenols with different substituents (R) in the para position with respect to the hydroxyl group, was synthesized. The photophysical properties of these species have been investigated in dichloromethane solution: they displayed intense fluorescence when excited with UV light (310–340 nm), with λmax of emission varying in the range 430–530 nm and lifetime decay of few nanoseconds. A very large Stokes shift (up to 189 nm) and high absolute quantum yields (up to 0.72) were recorded for most of the compounds. Moreover, good tuning of the emission is observed according to the electronic features of the substituent R, and a linear correlation was found between the emission maxima of the compounds and the Hammett σp constants of R. Two of these (tetrahydroimidazo[1,5-a]pyridin-3-yl)phenols were then chosen for preliminary measurements of their photophysical properties when dispersed in a host polymeric matrix (PMMA).
2018
Imidazo[1,5-a]pyridines Fluorescence Substituent effect Stokes shift Luminescent downshifting
Marchesi, Arianna; Brenna, Stefano; Attilio Ardizzoia, G.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2074108
 Attenzione

L'Ateneo sottopone a validazione solo i file PDF allegati

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 17
  • ???jsp.display-item.citation.isi??? 17
social impact