S1 Electronic Supplementary Information Rationally controlled helical organization of a multiple-hydrogen-bonding oligothiophene: guest-induced transition of helical-to-twisted ribbons Shiki Yagai,* a Marina Gushiken, a Takashi Karatsu, a Akihide Kitamura, a Yoshihiro Kikkawa b a Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. Fax: +81-(0)43-290-3039; Tel: +81-(0)43-290-3368; E-mail: yagai@faculty.chiba-u.jp b Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2010