Carbazole‐Terpyridine Donor‐Acceptor Dyads with Rigid π‐Conjugated Bridges. Issue 9 (8th July 2019)

• Record Type: Journal Article
• Authors: Matteucci, Elia; Baschieri, Andrea; Sambri, Letizia; Monti, Filippo; Pavoni, Eleonora; Bandini, Elisa; Armaroli, Nicola
• Is Part Of: ChemPlusChem. Volume 84:Issue 9(2019)
• Page Start: 1353
• Page End: 1365
• Publication Date: 2019-07-08
• Subjects: carbazole -- donor-acceptor dyads -- fluorescence -- π-conjugated systems -- terpyridines; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cplu.201900213
• Languages: English
• ISSNs: 2192-6506

Abstract

Abstract: A series of molecules in which 9 H ‐carbazole (electron donor, D) and 2, 2′:6′, 2′′‐terpyridine (electron acceptor, A) are connected through rigid π‐conjugated bridges (D‐π‐A systems) have been synthesized and their photophysical properties examined in detail, with the support of DFT calculations. The bridges are made of different sequences of ethynylene, phenylene, and anthracene groups. The synthetic strategies involve condensation of 2‐acetylpyridine with the aromatic aldehyde moiety on different functionalized π‐conjugated bridges and couplings with carbazole derivatives. The system incorporating anthracene in the bridge shows the typical absorption and emission fingerprints of this polycyclic hydrocarbon. The other systems have HOMOs and LUMOs centred, respectively, over the carbazole and the bridge and exhibit solvatochromic charge‐transfer (CT) luminescence with high photoluminescence yield up to 70 %, except when an ethynylene unit is directly attached to the carbazole ring, due to a trans ‐bent non‐emissive π–σ* excited state. Abstract : D‐π‐A systems : Seven carbazole‐terpyridine π‐bridged donor‐acceptor systems have been synthesized and characterized. With the help of DFT calculations, the correlation between the specific structure of the bridge and the photophysical properties of the whole systems has been fully elucidated.