title: Cyclo-oligomerization of 6,12-Diethynyl Indeno[1,2-b]fluorenes via Diradical Intermediates.
abstract: Indeno[1,2-b]fluorene derivatives with trimethylsilylethynyl substituents at the 6- and 12-positions were found to undergo cyclo-dimerization, cyclo-trimerization, and higher oligomerizations at room temperature. The cyclic dimer features a novel double-decker motif, composed of two face-to-face stacked bis(propadienylide)dihydroindeno[1,2-b]fluorenes with a short centroid-to-centroid distance of 3.50 Å. The existence of a cyclic trimer and higher oligomers was confirmed by mass spectroscopy and gel permeation chromatography. The results clearly demonstrate the diradical feature of the indeno[1,2-b]fluorene moiety.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, Center for the Soft Matter Science and Engineering and the Key Lab of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University , Beijing 100871, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Fu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, Center for the Soft Matter Science and Engineering and the Key Lab of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University , Beijing 100871, China.
authors.forename: Dahui
authors.initials: D
authors.lastname: Zhao