@article{oai:nagoya.repo.nii.ac.jp:00024730,
 author = {Fujikawa, Takao and Mitoma, Nobuhiko and Wakamiya, Atsushi and Saeki, Akinori and Segawa, Yasutomo and Itami, Kenichiro},
 issue = {21},
 journal = {Organic & Biomolecular Chemistry},
 month = {Jun},
 note = {The synthesis and properties of a new π-extended double [6]helicene 2 and a dithia[6]helicene 3 are described. Compared to the previously reported parent double-helicene molecule 1, the introduction of n-butyl groups successfully improved the solubility, which allowed an experimental investigation into the electronic structure of 2 and 3 by photophysical measurements and cyclic voltammetry. The characteristic two-blade propeller structures of 2 and 3 were unambiguously determined by single-crystal X-ray diffraction analysis. The crystal packing structure of 2 exhibited a contorted two-dimensional stacking, whereby molecules of n-pentane were incorporated in the stacks. Despite the presence of n-butyl groups, 3 formed a unique three-dimensional stacking lattice in the crystal. Time-resolved microwave conductivity measurements revealed that the double helicenes (1–3) exhibited transient conductivities. An organic field-effect transistor fabricated using 3 was found to function as a p-type transistor.},
 pages = {4697--4703},
 title = {Synthesis, properties, and crystal structures of π-extended double [6]helicenes: contorted multi-dimensional stacking lattice},
 volume = {15},
 year = {2017}
}