title: Dithieno[3,4-b:3',4'-d]thiophene-annelated antiaromatic planar cyclooctatetraene with olefinic protons.
abstract: The design and synthesis of a new planar cyclooctatetraene (COT) with protons directly connected to the COT ring was attained by monoannelation with dithieno[3,4-b:3',4'-d]thiophene. The planar structure of the COT core was unambiguously confirmed by X-ray crystallography. The magnetic antiaromaticity of the COT core was found to be higher than that of the previously synthesized planar COTs with olefinic protons, according to the results of (1)H NMR and absorption spectra as well as NICS calculations.
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Aita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohmae
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Takase
authors.forename: Kotohiro
authors.initials: K
authors.lastname: Nomura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kimura
authors.forename: Tohru
authors.initials: T
authors.lastname: Nishinaga
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D034242:Cyclooctanes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011522:Protons; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D000475:Alkenes; D034242:Cyclooctanes; D011522:Protons; D013876:Thiophenes; C534209:1,3,5,7-cyclooctatetraene