A photophysical and spectroelectrochemical study on N -phenyl-carbazoles and their oxidized species

RAMÍREZ, CRISTINA LUJÁN; MANGIONE, MARÍA INÉS; BERTOLOTTI, SONIA GRACIELA; ARBELOA, ERNESTO MAXIMILIANO; PARISE, ALEJANDRO RUBÉN

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

ELSEVIER SCIENCE SA

Año: 2018 vol. 365 p. 199 - 207

1010-6030

A series of N-phenyl-carbazole derivatives namely TCz (N-tolyl-carbazol), TCz-TCz (a 3,3´-linked dimer), and CzPh-CH2-PhCz (a methylene-bridged N-phenyl-carbazole), have been synthesized and studied by means of absorption and fluorescence spectra, DFT calculations, cyclic voltammetry and spectroelectrochemistry. It is concluded that the methylene bridge in CzPh-CH2-PhCz isolates the two TCz units, whereas TCz-TCz allowsextending the electronic coupling along both carbazoles. Moreover, the phosphorescence spectrum of TCz-TCz showed a high energy triplet state (2.76 eV). It was observed that oxidation of CzPh-CH2-PhCz generates an electrochromic polymer containing TCz-TCz dimer units separated by methylene bridges. Oxidized TCz-TCz subunit was analyzed by EPR spectroscopy, and found to be a Class III mixed valence ion in Robin and Dayclassification. All results suggest that these molecules might be suitable as selective probes in fluorescencesensing or as host materials in electroluminescent devices.