title: Star-shaped polycyclic aromatics based on oligothiophene-functionalized truxene: synthesis, properties, and facile emissive wavelength tuning.
abstract: A facile approach to soluble star-shaped oligothiophene-functionalized polycyclic aromatics based on truxene is developed in this Communication. The Suzuki coupling reactions afford the thiophene-containing polycyclic aromatics with long branches (about 2.1 nm length from the heart to the periphery) from truxene precursor with excellent yields. The unsubstituted alpha-positions of thiophene rings allow for efficient halogenation and for further functionalization. The investigation of proton NMR spectra indicates that the hexahexyl groups efficiently prevent the self-association through the arene-arene pi-stacking. Chemical shifts belonging to methylene groups move more upfield than do those of methyl groups. These chemical shift values (about 0.5-0.6 ppm) are quite lower than those of normal methyl and methylene groups. We also prepare a dendritic hyperbranched polymer P1 through FeCl3 mediated oxidative polymerizations. The photophysical properties of all compounds possessing good symmetry are investigated by UV-vis and emission measurement.
authors.affiliation: The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China. jianpei@chem.pku.edu.cn
authors.forename: Jian
authors.initials: J
authors.lastname: Pei
authors.forename: Jin-Liang
authors.initials: JL
authors.lastname: Wang
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Cao
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Zhou
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Zhang