title: Synthesis and photodynamics of fluorescent blue BODIPY-porphyrin tweezers linked by triazole rings.
abstract: Novel zinc porphyrin tweezers in which two zinc porphyrins were connected with π-conjugated boron dipyrromethenes (BDP meso-Por(2) and BDP β-Por(2)) through triazole rings were synthesized to investigate the photoinduced energy transfer and electron transfer. The UV-vis spectrum of BDP β-Por(2) which has less bulky substituents than BDP meso-Por(2) exhibits splitting of the Soret band as a result of the interaction between porphyrins of BDP β-Por(2) in the excited state. Such interaction between porphyrins of both BDP β-Por(2) and BDP meso-Por(2) is dominant at room temperature, while the coordination of the nitrogen atoms of the triazole rings to the zinc ions of the porphyrins occurs at low temperature. The conformational change of the BDP-porphyrin composites was confirmed by the changes in UV-vis and fluorescence spectra depending on temperature. Photodynamics of BDP meso-Por(2) and BDP β-Por(2) has also been investigated by laser flash photolysis. Efficient singlet-singlet energy transfer from the ZnP to the π-conjugated BDP moiety of both BDP meso-Por(2) and BDP β-Por(2) occurred in opposite direction as compared to energy transfer from conventional BDP to ZnP due to the π-conjugation in nonpolar toluene. In polar benzonitrile, however, additional electron transfer occurred along with energy transfer.
authors.affiliation: ICMUB, UMR CNRS 6302, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Eggenspiller
authors.forename: Atsuro
authors.initials: A
authors.lastname: Takai
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: El-Khouly
authors.forename: Kei
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Claude P
authors.initials: CP
authors.lastname: Gros
authors.forename: Claire
authors.initials: C
authors.lastname: Bernhard
authors.forename: Christine
authors.initials: C
authors.lastname: Goze
authors.forename: Franck
authors.initials: F
authors.lastname: Denat
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Barbe
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi
mesh_terms: D001896:Boron Compounds; D004735:Energy Transfer; D008665:Metalloporphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D052898:Optical Tweezers; D010777:Photochemistry; D013057:Spectrum Analysis; D014230:Triazoles; D015032:Zinc
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D008665:Metalloporphyrins; D014230:Triazoles; D015032:Zinc