TY - JOUR
T1 - Cross-conjugated oligothiophenes derived from the (C2S) n helix
T2 - Asymmetric synthesis and structure of carbon-sulfur [11]helicene
AU - Miyasaka, Makoto
AU - Rajca, Andrzej
AU - Pink, Maren
AU - Rajca, Suchada
PY - 2005/10/12
Y1 - 2005/10/12
N2 - (-)-Sparteine-mediated asymmetric synthesis of di-n-octyl-substituted carbon-sulfur [11]helicene, a helical (C2S)n β-undecathiophene, is described. The atom-efficient routes rely on one-step tri-annelation or two-step di- and mono-annelation to provide enantiomeric excess of (+)- or (-)-[11]helicene, respectively. X-ray structures for homologous [11] and [7]helicenes indicate similar helical curvatures. The optical band gap, Eg ≈ 3.5 eV, is estimated for the (C2S)n helix polymer, with onset of electron localization at n ≤ 7.
AB - (-)-Sparteine-mediated asymmetric synthesis of di-n-octyl-substituted carbon-sulfur [11]helicene, a helical (C2S)n β-undecathiophene, is described. The atom-efficient routes rely on one-step tri-annelation or two-step di- and mono-annelation to provide enantiomeric excess of (+)- or (-)-[11]helicene, respectively. X-ray structures for homologous [11] and [7]helicenes indicate similar helical curvatures. The optical band gap, Eg ≈ 3.5 eV, is estimated for the (C2S)n helix polymer, with onset of electron localization at n ≤ 7.
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U2 - 10.1021/ja055414c
DO - 10.1021/ja055414c
M3 - Article
C2 - 16201798
AN - SCOPUS:26444448373
SN - 0002-7863
VL - 127
SP - 13806
EP - 13807
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 40
ER -