title: A hybrid macrocycle with a pyridine subunit displays aromatic character upon uranyl cation complexation.
abstract: Reported here is a new hybrid macrocycle, cyclo[1]furan[1]pyridine[4]pyrrole (1), that bears analogy to the previously reported mixed heterocycle system cyclo[2]pyridine[4]pyrrole (2) and cyclo[6]pyrrole 3, an all-pyrrole 22 π-electron aromatic expanded porphyrin. The oxidized, dianionic form of 1, [1 - 4H](2-), has been characterized as its uranyl complex. In contrast to 2 and 3 and in spite of the presence of a 2,6-disubstituted pyridine subunit, the uranyl complex of [1 - 4H](2-) displays solid-state structural and solution-phase spectroscopic features consistent with contributions to the overall electronic structure that involve a conjugated, (4n + 2) π-electron aromatic periphery.
authors.affiliation: Department of Chemistry, The University of Texas at Austin , 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224 United States.
authors.forename: I-Ting
authors.initials: IT
authors.lastname: Ho
authors.forename: Zhan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ishida
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Lynch
authors.forename: Won-Young
authors.initials: WY
authors.lastname: Cha
authors.forename: Young Mo
authors.initials: YM
authors.lastname: Sung
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Sessler