title: The synthesis and properties of free-base [14]triphyrin(2.1.1) compounds and the formation of subporphyrinoid metal complexes.
abstract: The synthesis of [14]triphyrin(2.1.1) compounds is described. In contrast with conventional subporphyrins, which consistently contain a central boron atom, free-base heteroaromatic compounds can be formed. A modified Lindsey method was used to prepare a range of different [14]triphyrins(2.1.1) in yields of up to 35% based on the reaction of diethylpyrrole (1a) and fused pyrroles of bicyclo[2.2.2]octadiene (BCOD) (2a-e) and dihydroethanonaphthalene (4a) with various aryl aldehydes. The concentration of BF(3)·OEt(2) catalyst plays the key role in determining the yield of the [14]triphyrin(2.1.1) macrocycle relative to the conventional tetrapyrrole porphyrin product. Retro-Diels-Alder reactions of 2a-e and 4a result in the formation of [14]tribenzotriphyrin (2.1.1) (3a-e) and [14]trinaphthotriphyrin(2.1.1) (5a). The effects of exocyclic ring annulation on the electronic structure are examined in detail based on optical spectroscopy, theoretical calculations, and electrochemical measurements. The availability of free-base compounds enables the formation of [Re(I)(CO)(3)(triphyrin)] (6a) and [Ru(II)(CO)(2)Cl(triphyrin)] (7a) complexes based on a modified retro-Diels-Alder reaction. X-ray structures are reported for 4a and 6a.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Zhao Li
authors.initials: ZL
authors.lastname: Xue
authors.forename: John
authors.initials: J
authors.lastname: Mack
authors.forename: Hua
authors.initials: H
authors.lastname: Lu
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiao Zeng
authors.initials: XZ
authors.lastname: You
authors.forename: Daiki
authors.initials: D
authors.lastname: Kuzuhara
authors.forename: Martin
authors.initials: M
authors.lastname: Stillman
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamada
authors.forename: Seigo
authors.initials: S
authors.lastname: Yamauchi
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Zhen
authors.initials: Z
authors.lastname: Shen