Tetrahedral oligothiophenes; synthesis, X-ray analysis, and optoelectronic properties of highly symmetrical, 3D-branched oligothiophenes.
Tetrakis(bithienyl)methane and tetrakis(terthienyl)methane have been synthesized from tetrakis(2-thienyl)methane by use of Suzuki-Miyaura coupling as a key reaction. Their trimethylsilyl (TMS) derivatives are also synthesized. X-ray analysis reveals that each oligothiophene moiety tends to adopt anti-conformations and show relatively small torsion angles between the adjacent thiophene rings. While the longest absorption maxima of these tetrakis(oligothienyl)methanes exhibit only a slight bathochromic shift compared to the corresponding linear oligothiophene derivative, tetrakis(bithienyl)methane and its TMS derivative exhibit an appreciable red-shift in their fluorescence spectra. The intramolecular interaction between thienyl groups of tetrakis(2-thienyl)methane is supported by DFT calculation.
Graduate School of Science, Osaka University, Toyonaka, Osaka (Japan). kmatsu@chem.sci.osaka-u.ac.jp
Kouzou
K
Matsumoto
Toru
T
Tanaka
Sota
S
Kugo
Takuya
T
Inagaki
Yoshikazu
Y
Hirao
Hiroyuki
H
Kurata
Takeshi
T
Kawase
Takashi
T
Kubo