title: Characterisation of dihydroazulene and vinylheptafulvene derivatives using Raman spectroscopy: The CN-stretching region.
abstract: The effect of adding electron donating and withdrawing groups on the dihydroazulene (DHA)/vinylheptafulvene (VHF) photochromic system has been investigated using Raman spectroscopy in CS2 solutions. The photoswitching between DHA and VHF is often characterised with UV-Vis spectroscopy. However, Raman spectroscopy can also be used for this purpose and give structural insight, as the light induced ring-opening from DHA to VHF causes changes in the CN-stretching frequencies. The CN-stretching frequencies in DHA and VHF are isolated and optimal for the identification of DHA and VHF. The DHA system is also investigated in the solid state.
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Hansen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Mackeprang
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Søren L
authors.initials: SL
authors.lastname: Broman
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Mia Harring
authors.initials: MH
authors.lastname: Hansen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Anders S
authors.initials: AS
authors.lastname: Gertsen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Jens V
authors.initials: JV
authors.lastname: Kildgaard
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Ole Faurskov
authors.initials: OF
authors.lastname: Nielsen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Mikkelsen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Mogens Brøndsted
authors.initials: MB
authors.lastname: Nielsen
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark. Electronic address: hgk@chem.ku.dk.
authors.forename: Henrik G
authors.initials: HG
authors.lastname: Kjaergaard
keywords: CN-stretching vibration; Photoswitch; Raman spectroscopy; Solution and solid phase