title: Double homologation method for substituted soluble pentacenes and dimerization behaviours of pentacenes.
abstract: Double up: A zirconium-mediated double homologation method was successfully applied for the synthesis of multi-substituted pentacene derivatives from 1,2,4,5-tetrakis(propargyl)benzenes. The bis(zirconacyclopentadiene) intermediates were also characterized. Among these symmetrical derivatives, tetra- and octa-substituted pentacenes undergo reversible conversion between monomeric and dimeric forms. A double homologation method for the formation of substituted soluble pentacenes was developed by a zirconium-mediated cyclization of tetrayne derivatives. Thermal dimerization of tetra- and octasubstituted pentacenes was observed. The dimerization behavior was observed to be strongly related to the substituent groups affixed to the pentacenes.
authors.affiliation: Catalysis Research Center, Hokkaido University, and SORST, Japan Science and Technology Agency (JST), Kita 21, Nishi 10, Kita-ku, Sapporo 001-0021, Japan.
authors.forename: Shi
authors.initials: S
authors.lastname: Li
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Nakajima
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Kanno
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Takahashi