Pyrene-based color-tunable dipolar molecules: Synthesis, characterization and optical properties Chuan-Zeng Wang Xing Feng Zannatul Kowser Chong Wu Thamina Akther Mark Elsegood Carl Redshaw Takehiko Yamato 2134/32670 https://repository.lboro.ac.uk/articles/journal_contribution/Pyrene-based_color-tunable_dipolar_molecules_Synthesis_characterization_and_optical_properties/9394424 © 2018 Elsevier Ltd A controllable regioselective approach to achieve dipolar functionalization at the active sites (1,3-positions) and K-region (5,9-positions) of pyrene is demonstrated. Following this strategy, a set of dipolar 1,3-diphenyl-5,9-di(4-R-phenylethynyl)pyrenes were synthesized and systematically investigated by 1 H/ 13 C NMR spectroscopy, X-ray crystallography, electronic spectra, as well as by theoretical calculations. By adjusting the substituents at the 5,9-positions of pyrene, the pyrene-based dipolar molecules 4 (H, F, OMe, CN, CHO, NMe 2 ) exhibit tunable optical properties with a wide emission band from blue (437 nm) to orange-red (571 nm). 2018-04-23 08:19:45 Regioselective synthesis Pyrene chemistry K-region Tunable emission Dipolar molecules Chemical Sciences not elsewhere classified