Intermolecular Hydrogen Bonding in the Fluorescence Excited State of Organic Luminophores Containing Both Carbonyl and Amino Groups

Abstract

The radiationless deactivation of the excited states of organic luminophores as a result of specific intra-or intermolecular interactions (intramolecular charge transfer; formation of excimers and exciplexes; formation of hydrogen bonds) has been studied by many authors (see, for instance, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]). Some of these investigations are devoted to the possible formation of intermolecular hydrogen bonds in the excited state between the molecules of the substance and the protic solvents [5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The conclusions are based on analysis of the specific photophysical properties of the studied compounds in solvents of different polarity and protondonating ability.The present review is a generalization of our previously published investigations on the deactivation processes of the excited states of 5-aminoindan-1,3-diones (AID) [11], 5-amino-3-hetarylmethylene-1(3H)-isobenzofuranones (HAB) [12], 10-decyl-and 10-propenyl-9-acridanones (ACR) [13], 3-arylmethylene-1(3H)-isobenzofuranones (benzylidenephthalides, BPH) and 5-amino-3-arylmethylene-1(3H)-isobenzofuranones (aminobenzylidenephthalides, ABPH) [14] and synthetic chalcones [17]. All these groups of compounds are characterized by the presence both of a carbonyl group and an electron-donating substituent in a common conjugated system.