title: Energy transfer in aggregates of bacteriochlorophyll c self-assembled with azulene derivatives.
abstract: Bacteriochlorophyll (BChl) c is the main light-harvesting pigment of certain photosynthetic bacteria. It is found in the form of self-assembled aggregates in the so-called chlorosomes. Here we report the results of co-aggregation experiments of BChl c with azulene and its tailored derivatives. We have performed spectroscopic and quantum chemical characterization of the azulenes, followed by self-assembly experiments. The results show that only azulenes with sufficient hydrophobicity are able to induce aggregation of BChl c. Interestingly, only azulene derivatives possessing a conjugated phenyl ring were capable of efficient (∼50%) excitation energy transfer to BChl molecules. These aggregates represent an artificial light-harvesting complex with enhanced absorption between 220 and 350 nm compared to aggregates of pure BChl c. The results provide insight into the principles of self-assembly of BChl aggregates and suggest an important role of the π-π interactions in efficient energy transfer.
authors.affiliation: Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague, Czech Republic. psencik@karlov.mff.cuni.cz.
authors.forename: Martina
authors.initials: M
authors.lastname: Matěnová
authors.forename: Viviana
authors.initials: V
authors.lastname: Lorelei Horhoiu
authors.forename: Florian-Xuan
authors.initials: FX
authors.lastname: Dang
authors.forename: Petr
authors.initials: P
authors.lastname: Pospíšil
authors.forename: Jan
authors.initials: J
authors.lastname: Alster
authors.forename: Jaroslav V
authors.initials: JV
authors.lastname: Burda
authors.forename: Teodor Silviu
authors.initials: TS
authors.lastname: Balaban
authors.forename: Jakub
authors.initials: J
authors.lastname: Pšenčík
mesh_terms: D052176:Azulenes / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D001429:Bacteriochlorophylls / Q000737:chemistry*; D004735:Energy Transfer
chemical_list: D052176:Azulenes; D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; C002084:bacteriochlorophyll c; C005525:azulene