Effect of heteroatom exchange (S/Se) in the mesomorphism and physical properties of benzochalcogenodiazole-based liquid crystals

Synthesis of 2,1,3-Benzoxadiazole Derivatives as New Fluorophores—Combined Experimental, Optical, Electro, and Theoretical Study

“…The values obtained are summarized in Table 1, where it can be noted that all compounds presented quantum yields (Φ FL ) of 0.51 to 0.54. The values obtained for compounds 9a-d are considerably higher than those reported in our previous articles for compounds containing the heterocycles 2,1,3-benzoselenadiazole (Regis et al, 2018) and 2,1,3-benzotiadiazole (Frizon et al, 2016).…”

“…Conjugated organic compounds, such as benzochalcogenodiazoles, have attracted attention because of their versatility and advantages, including low cost, improved electronic device performance, flexibility, and tuning through structural design (Liu et al, 2015). This class of compounds has been applied in field-effect transistors, sensors, memory devices, and solar cells (Regis et al, 2018). In general, the incorporation of heterocyclic units with electron-donating groups (donors) and electron-accepting groups (acceptors) in the molecular structure increases the conjugation and alters the performance of organic electronic devices (Niu et al, 2007;Fu et al, 2009;Liu et al, 2015).…”

“…The BOX heterocycle, also known as benzofuran, has a flat molecular and bicyclic conjugated structure, and its derivative compounds with extended conjugates are extremely fluorescent. Because of the presence of an oxygen atom in the heterocycle, BOX is more electronegative when compared to BTD (Bouffard and Swager, 2008;Lin et al, 2011;Zeng et al, 2012;Göker et al, 2014;Regis et al, 2018), and due to this electronegativity, BOX forms coplanar and quinoid structures, giving better stability to the devices manufactured (Liu et al, 2015).…”

“…The main applications of BOX are to obtain fluorescent derivatization reagents and use in the detection of heavy metals (Toyo'oka, 2004;Song et al, 2011;Sumiya et al, 2011), in solar cells, and in liquid crystals (Liu et al, 2015;Regis et al, 2018).…”

“…As part of our continued involvement in the chemistry of Nheterocycles (Saba et al, 2015(Saba et al, , 2016(Saba et al, , 2017(Saba et al, , 2018(Saba et al, , 2020Rafique et al, 2016Rafique et al, , 2018aSilva et al, 2017;Bettanin et al, 2018;Peterle et al, 2018;Rodigues et al, 2018;Tornquist et al, 2018;Meirinho et al, 2019;Neto et al, 2020;Scheide et al, 2020) and material sciences (Frizon et al, 2014(Frizon et al, , 2015(Frizon et al, , 2016(Frizon et al, , 2018Bo et al, 2016Bo et al, , 2018Westrup et al, 2016;Matzkeit et al, 2018;Regis et al, 2018), herein, we report the synthesis and characterization of BOX derivatives containing electrondonor groups (alkylated tetrazole rings) connected to the 2,1,3-BOX group as an electron-acceptor unit. In addition, thermal, electrochemical, and theoretical predictions were made and photophysical analysis was performed to study the stability, likely geometry, and luminescence properties of these compounds in their ground and excited electronic states.…”