title: Picosecond structural relaxation of abietic acid based amine end capped para-phenylenevinylene trimers in solution.
abstract: The synthesis and photophysical properties of six new abietic acid based amine end-capped p-phenylenevinylene trimers (AECPV3) in their lowest excited singlet states are presented. The AECPV3 compounds show a large red-shift of both the absorption (25-30 nm) and emission (37-42 nm) maxima with respect to those of the corresponding trimers. Picosecond time-resolved fluorescence data reveal the presence of a fast conformational relaxation process (40-62 ps) of the initially excited compounds, leading to more planar conformers. The conformational relaxation time is proportional to the volume of both the side chain and the amine groups.
authors.affiliation: Centro de Química Estrutural, Departamento de Engenharia Química e Biológica, Instituto Superior Técnico, Lisboa, Portugal. roberto.paolo@ist.utl.pt
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Di Paolo
authors.forename: Barbara
authors.initials: B
authors.lastname: Gigante
authors.forename: Maria A
authors.initials: MA
authors.lastname: Esteves
authors.forename: Natércia
authors.initials: N
authors.lastname: Pires
authors.forename: Célia
authors.initials: C
authors.lastname: Santos
authors.forename: Maria H
authors.initials: MH
authors.lastname: Lameiro
authors.forename: João Seixas
authors.initials: JS
authors.lastname: de Melo
authors.forename: Hugh D
authors.initials: HD
authors.lastname: Burrows
authors.forename: António L
authors.initials: AL
authors.lastname: Maçanita
mesh_terms: D045784:Abietanes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D005453:Fluorescence; D008968:Molecular Conformation; D010777:Photochemistry; D011145:Polyvinyls / Q000138:chemical synthesis / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013696:Temperature; D013997:Time Factors
chemical_list: D045784:Abietanes; D000588:Amines; D011145:Polyvinyls; D012996:Solutions; D012997:Solvents; C470024:poly(4-phenylenevinylene); C023710:abietic acid