title: Synthesis of nanostructures based on 1,4- and 1,3,5-ethynylphenyl subunits with pi-extended conjugation. Carbon dendron units.
abstract: Nanometer-sized conjugated 1,4- and 1,3,5-ethynylphenyl oligomers were synthesized starting from 3,5-di(trimethylsilylethynyl)phenylacetylene and p-[3,5-di(trimethylsilylethynyl)-1-ethynylphenyl]phenyl acetylene by cross-coupling reaction with a convenient haloaryl derivative, catalyzed by palladium(II)/copper(I), in excellent yield. The terminal acetylenes were efficiently prepared by a specific protection-deprotection methodology. All ethynylphenyl homologues obtained show fluorescence emission, with the bathochromic shift of approximately 20 nm by each ethynylphenyl unit increasing the conjugate chain. Parallel conjugated ethynylphenyl chains were prepared through the insertion of a 1,5-naphthalene subunit, and the compounds exhibit fluorescence radiation emission.
authors.affiliation: Departamento Química Orgánica, Facultad de Ciencias, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain. gonzalo.rodriguez@uam.es
authors.forename: J Gonzalo
authors.initials: JG
authors.lastname: Rodríguez
authors.forename: Jorge
authors.initials: J
authors.lastname: Esquivias
authors.forename: Antonio
authors.initials: A
authors.lastname: Lafuente
authors.forename: Cristina
authors.initials: C
authors.lastname: Díaz