Unravelling the intricate photophysical behavior of 3-(pyridin-2-yl)triimidazotriazine AIE and RTP polymorphs. Issue 29 (17th June 2020)

• Record Type: Journal Article
• Authors: Lucenti, Elena; Forni, Alessandra; Previtali, Andrea; Marinotto, Daniele; Malpicci, Daniele; Righetto, Stefania; Giannini, Clelia; Virgili, Tersilla; Kabacinski, Piotr; Ganzer, Lucia; Giovanella, Umberto; Botta, Chiara; Cariati, Elena
• Is Part Of: Chemical science. Volume 11:Issue 29(2020)
• Page Start: 7599
• Page End: 7608
• Publication Date: 2020-06-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0sc02459g
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : TT-Py exhibits anti-Kasha and multiple emissive behaviour due to the copresence of rigid TT and partially conformationally free Py . Abstract : The development of purely organic materials showing multicolor fluorescent and phosphorescent behaviour represents a formidable challenge in view of practical applications. Herein the rich photophysical behaviour of 3-(pyridin-2-yl)triimidazotriazine (TT-Py ) organic molecule, comprising excitation-dependent fluorescence and phosphorescence under ambient conditions in both blended films and the crystalline phase, is investigated by means of steady state, time resolved and ultrafast spectroscopies and interpreted on the basis of X-ray diffraction studies and DFT/TDDFT calculations. In particular, by proper excitation wavelength, dual fluorescence and dual phosphorescence of molecular origin can be observed together with low energy phosphorescences resulting from aggregate species. It is demonstrated that the multiple emission properties originate from the copresence, in the investigated system, of an extended polycyclic nitrogen-rich moiety (TT ), strongly rigidified by π–π stacking interactions and short C–H⋯N hydrogen bonds, and a fragment (Py ) having partial conformational freedom.