| Abstract [eng] |
Organic luminescent materials have attracted increasing attention for their potential applications in the fields of organic light emitting diodes and sensors. Employment of materials exhibiting thermally activated delayed fluorescence and room temperature phosphorescence in the active layers of organic light emitting diodes has been stated to be very efficient, due to possible use of 100 % of excitons. In addition to organic diode applications, thermally activated delayed fluorescent emitters due to the long lifetime of fluorescence, and room temperature phosphorescent emitters are promising candidates for bio imaging and sensing of different analyte, such as oxygen. In this work, bis(trifluoromethyl)biphenyl-based emitters with various donor moieties, such as carbazole, dimethylacridan, phenothiazine, are presented. Bis(trifluoromethyl)biphenyl acceptor and various donor fragments were chosen for the synthesis of novel electroactive compounds exhibiting thermally activated delayed emission and room temperature phosphorescence phenomena. A two-step synthetic route was chosen to obtain the target compounds. Thermal, photophysical, electrochemical, and photoelectrical properties of the compounds were analyzed and presented. Bis(trifluoromethyl)biphenyl-based emitters are suitable to be used in active layers of organic light emitting diodes due to the fact that thermal stability of the synthesized compounds reaches 397–442 ℃ together with glass-transition temperatures in the range of 152–248 ℃. Compounds were found to be electrochemically stable with reverse oxidation and reduction. 9,9‘-[2,2‘-bis(trifluoromethyl)-biphenyl-4,4‘-diil]bis(phenothiazine) had the lovest ionization energy of 5.05 eV. 9,9‘-[2,2‘-bis(trifluoromethyl)-biphenyl-4,4‘-diil]bis(phenothiazine) also exhibits room temperature phosphorecence, thus this compound can be used in structure of oxygen sensors. Synthesized compounds emit violet – blue light. |
