title: Tubular exciton models for BChl c antennae in chlorosomes from green photosynthetic bacteria.
abstract: Exciton calculations on tubular pigment aggregates similar to recently proposed models for BChl c/d/e antennae in light-harvesting chlorosomes from green photosynthetic bacteria yield electronic absorption spectra that are super-impositions of linear J-aggregate spectra. While the electronic spectroscopy of such antennae differs considerably from that of linear J-aggregates, tubular exciton models (which may be viewed as cross-coupled J-aggregates) may be constructed to yield spectra that resemble that of the BChl c antenna in the green bacterium Chloroflexus aurantiacus. Highly symmetric tubular models yield absorption spectra with dipole strength distributions essentially identical to that of a J-aggregate; strong symmetry-breaking is needed to simulate the absorption spectrum of the BChl c antenna.
authors.affiliation: Ames Laboratory-USDOE, Iowa State University, 50011, Ames, IA, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Buck
authors.forename: W S
authors.initials: WS
authors.lastname: Struve