title: Oxidative coupling of 1,7,8-unsubstituted BODIPYs: synthesis and electrochemical and spectroscopic properties.
abstract: We report the synthesis of BODIPYs with unsubstituted 1,7,8-positions and their dimerization by oxidative coupling with phenyliodine(III)-bis(trifluoroacetate) (PIFA). This dimerization was achieved for BODIPYs substituted in the 3,5-positions with either methyl or thienyl groups. The position and the type of the linkage in the resulting dimers depended on the nature of the substituent. The 3,5-dimethyl-BODIPY dyes were linked either via direct 1,1'-pyrrole-pyrrole coupling or via a 1,3'-methylene bridge. The 3,5-dithienyl-BODIPY dyes provided, in excellent yields, unique compounds linked exclusively via the α-thienyl positions. All dyes were unreactive in the 8-position. Electrochemical and spectroscopic measurements on the monomers and dimers provided evidence of interactions between the two halves of the dimers. Thus, oxidation and reduction potentials were split by up to 210 mV, and modest excitonic coupling and an internal charge transfer were observed in some cases.
authors: Laboratoire de Chimie Organique et Spectroscopies Avancées, UMR 7515 au CNRS, École de Chimie, Polymères et Matériaux de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg, Cedex 02, France.
authors: Arnaud
authors: A
authors: Poirel
authors: Antoinette
authors: A
authors: De Nicola
authors: Pascal
authors: P
authors: Retailleau
authors: Raymond
authors: R
authors: Ziessel
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D055664:Electrochemical Techniques; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013055:Spectrophotometry, Infrared
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D004396:Coloring Agents