Influence of Chlorine Substitution on the Structures and Photophysical Properties of 9,10-Distyrylanthracene (DSA).

In order to investigate the influence of chlorine substituent on the structures and optical properties of 9,10-distyrylanthracene (DSA), a series of chlorinated DSA derivatives, namely,9, 10-bis(2-chlorostyryl)anthracene (2-BCSA), 9, 10-bis(3-chlorostyryl)anthracene (3-BCSA), 9, 10-bis(4-chlorostyryl)anthracene (4-BCSA), 9, 10-bis(3, 5-dichlorostyryl)anthracene (BDCSA) were synthesized and characterized, assisted by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The results indicate that intermolecular interactions and molecular packing modes can be affected effectively by the chlorine substituent. Similar to that of DSA, strengthening C-H…π intermolecular interactions were formed within the 2-BCSAcrystal. However, C-H…π intermolecular interactions are negligible in the other chlorinated derivatives. In particular, π…π intermolecular interactions exist within the 3-BCSAandBDCSAcrystals. Especially, BDCSAmolecules display a discrete π-π anthracene dimer stacking mode. In addition, J-aggregation mode of molecules are formed within the 4-BCSAcrystal. The different intermolecular interactions and molecular packing modes lead to their different photophysical properties. Furthermore, theory calculations indicate that the electron excitations of all compounds mainly occur within the anthracene moieties. This study sheds light on the modulation of photophysical properties and structures of anthracene-based materials by chlorine substituent. In order to investigate the influence of chlorine substituent on the structures and optical properties of 9,10-distyrylanthracene (DSA), a series of chlorinated DSA derivatives, namely, 9, 10-bis(2-chlorostyryl)anthracene (2-BCSA), 9, 10-bis(3-chlorostyryl)anthracene (3-BCSA), 9, 10-bis(4-chlorostyryl)anthracene (4-BCSA), 9, 10-bis(3, 5-dichlorostyryl)anthracene (BDCSA) were synthesized and characterized, assisted by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The results indicate that intermolecular interactions and molecular packing modes can be affected effectively by the chlorine substituent. Similar to that of DSA, strengthening C-H…π intermolecular interactions were formed within the 2-BCSA crystal. However, C-H…π intermolecular interactions are negligible in the other chlorinated derivatives. In particular, π…π intermolecular interactions exist within the 3-BCSA and BDCSA crystals. Especially, BDCSA molecules display a discrete π-π anthracene dimer stacking mode. In addition, J-aggregation mode of molecules are formed within the 4-BCSA crystal. The different intermolecular interactions and molecular packing modes lead to their different photophysical properties. Furthermore, theory calculations indicate that the electron excitations of all compounds mainly occur within the anthracene moieties. This study sheds light on the modulation of photophysical properties and structures of anthracene-based materials by chlorine substituent.