title: Linear heterocyclic aromatic fluorescence compounds having various donor-acceptor spacers prepared by the combination of carbon-carbon bond and carbon-nitrogen bond cross-coupling reactions.
abstract: A family of novel linear 1,10-phenanthroline-based (A-D-A-D-A) and oligothiophene-based (A-D-D-D-(D)-A) heterocyclic aromatic fluorescence compounds having N-containing imidazole and pyridine tails with effective π-conjugated systems, prepared by the combination of carbon-carbon (C-C) bond and carbon-nitrogen (C-N) bond cross-coupling reactions, is described. They have molecular lengths of more than 2.30 nm in the cases of 4, 6, 9, and 26, various D-A spacers, and certain N-coordination sites (phen, imidazole, and pyridine). X-ray single-crystal structures of 13 compounds reveal a variety of trans and cis configurations with different dihedral angles between adjacent aromatic heterocycles. Synthetic, computational, and spectral studies have been made to reveal the differences between cross-coupling approaches on the C-C bond and C-N bond formation as well as band gaps and energy levels and optical and electrochemical properties for related compounds. The influences of introducing a β-methyl group to the thiophene ring on reaction activity, solubility, and conformation of related compounds have also been discussed.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, P R China.
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Fu
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Zhu
authors.forename: Kou-Sen
authors.initials: KS
authors.lastname: Cao
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Xiao-Zeng
authors.initials: XZ
authors.lastname: You