2024-03-28T16:52:28Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/845312022-11-17T02:08:08Zhdl_2115_20039hdl_2115_116Anthraquinodimethane Ring-Flip in Sterically Congested Alkenes : Isolation of Isomer and Elucidation of Intermediate through Experimental and Theoretical ApproachYusuke, IshigakiTomoki, TadokoroYu, HarabuchiHayashi, YukiMaeda, SatoshiSuzuki, TakanoriOvercrowded ethylenesIsomerizationArtificial force induced reaction437From the viewpoint of the development of molecular response systems, stimulus-induced switching of multi-conformational/multi-configurational overcrowded ethylenes are interesting, whose properties could be manipulated by understanding the detailed isomerization paths. Anthraquinodi-methane (AQD) ring-flip is usually a very fast process, and thus less studied experimentally. Herein, we studied AQDs with dibenzo- and tribenzocycloheptatrienylidene units, which have large enough steric hindrance to retard the AQD ring-flip to allow determination of the Delta G(not equal) value experimentally. Their thermal isomerization was also scrutinized using the artificial force induced reaction method to elucidate the intermediates. Based on the structural unsymmetry in a newly prepared AQD, one of the isomers that undergoes a reversible conformational change via AQD ring-flip was isolated and analyzed by X-ray for the first time.Journal Articlehttp://hdl.handle.net/2115/845310009-2673Bulletin of the Chemical Society of Japan95138462022enginfo:doi/10.1246/bcsj.20210355none