title: Towards a vibrational analysis of spheroidene. Resonance Raman spectroscopy of 13C-labelled spheroidenes in petroleum ether and in the Rhodobacter sphaeroides reaction centre.
abstract: We report resonance Raman spectra of the carotenoid spheroidene and its 14'-13C and 15'-13C substituted analogues in petroleum ether and bound to the reaction centre of Rhodobacter sphaeroides R26. The spectra in petroleum ether correspond to planar all-trans spheroidene while those of the reaction centres are consistent with a nonplanar 15,15'-cis spheroidene. The effect of 13C labelling is largest in the carbon-carbon double-bond stretching region. The 15'-13C substitution of the reaction centre bound spheroidene, however, hardly changes the C=C band as compared to that for the natural abundance spheroidene apart from a new weak band at 1508 cm(-1). This observation has been interpreted as a decoupling of the C15=C15' stretch from the other double-bond stretches in combination with a small intrinsic Raman intensity of this local mode for 15,15'-cis spheroidene.
authors.affiliation: Centre for the Study of Excited States of Molecules, Huygens Laboratory, Leiden University, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Kok
authors.forename: J
authors.initials: J
authors.lastname: Köhler
authors.forename: E J
authors.initials: EJ
authors.lastname: Groenen
authors.forename: R
authors.initials: R
authors.lastname: Gebhard
authors.forename: I
authors.initials: I
authors.lastname: van der Hoef
authors.forename: J
authors.initials: J
authors.lastname: Lugtenburg
authors.forename: A F
authors.initials: AF
authors.lastname: Hoff
authors.forename: R
authors.initials: R
authors.lastname: Farhoosh
authors.forename: H A
authors.initials: HA
authors.lastname: Frank
mesh_terms: D000473:Alkanes; D002250:Carbon Radioisotopes; D002338:Carotenoids / Q000737:chemistry*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D012242:Rhodobacter sphaeroides / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D000473:Alkanes; D002250:Carbon Radioisotopes; D045322:Photosynthetic Reaction Center Complex Proteins; C005637:spheroidene; D002338:Carotenoids; C004544:naphtha