title: Photoisomerization of stilbene dendrimers: the need for a volume-conserving isomerization mechanisms.
abstract: Highly branched stilbene dendrimers were synthesized and their photochemical behavior was studied. Even the stilbene dendrimer with molecular weight over 6500 underwent trans-cis isomerization in the excited singlet state within the lifetime of 10 ns. The photoisomerization of C=C double bond of stilbene dendrimers in the excited state may proceed by a volume-conserving novel mechanism such as hula-twist rather than conventional 180 degrees rotation around the C=C double bond based on fluorescence and isomerization experiments.
authors.affiliation: Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Uda
authors.forename: Takuo
authors.initials: T
authors.lastname: Mizutani
authors.forename: Junpel
authors.initials: J
authors.lastname: Hayakawa
authors.forename: Atsuya
authors.initials: A
authors.lastname: Momotake
authors.forename: Masashi
authors.initials: M
authors.lastname: Ikegami
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Nagahata
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Arai