title: Double head-to-tail direct arylation as a viable strategy towards the synthesis of the aza-analog of dihydrocyclopenta[hi]aceanthrylene--an intriguing antiaromatic heterocycle.
abstract: The first case of double head-to-tail direct arylation of aromatic compounds and the unusual photophysical properties of the resulting 2,2a(1,5)b(1,7)-tetraazacyclopenta[hi]aceanthrylene are reported. This molecule, comprising of two imidazo[1,2-a]pyridine units, is antiaromatic due to the changes in the efficiency of π-electron ring current and it belongs to a class of seldom encountered compounds with a dark lowest electronically excited singlet state.
authors.affiliation: Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Dikhi
authors.initials: D
authors.lastname: Firmansyah
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland. kozank@ifpan.edu.pl.
authors.forename: Irena
authors.initials: I
authors.lastname: Deperasińska
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. dtgryko@icho.edu.pl.
authors.forename: Olena
authors.initials: O
authors.lastname: Vakuliuk
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland. kozank@ifpan.edu.pl.
authors.forename: Marzena
authors.initials: M
authors.lastname: Banasiewicz
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. dtgryko@icho.edu.pl.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Tasior
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland. kozank@ifpan.edu.pl.
authors.forename: Artur
authors.initials: A
authors.lastname: Makarewicz
authors.affiliation: Warsaw University, Chemistry Department, Pasteura 1, 01-224 Warsaw, Poland. chamis@chem.uw.edu.pl.
authors.forename: Michał K
authors.initials: MK
authors.lastname: Cyrański
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland. kozank@ifpan.edu.pl.
authors.forename: Bolesław
authors.initials: B
authors.lastname: Kozankiewicz
authors.affiliation: Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland and Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. dtgryko@icho.edu.pl.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Gryko