600-28-2Relevant articles and documents
Functional panchromatic BODIPY dyes with near-infrared absorption: Design, synthesis, characterization and use in dye-sensitized solar cells
Huaulmé, Quentin,Aumaitre, Cyril,Kontkanen, Outi Vilhelmiina,Beljonne, David,Sutter, Alexandra,Ulrich, Gilles,Demadrille, Renaud,Leclerc, Nicolas
, p. 1758 - 1768 (2019)
We report two novel functional dyes based on a boron-dipyrromethene (BODIPY) core displaying a panchromatic absorption with an extension to the near-infrared (NIR) range. An innovative synthetic approach for preparing the 2,3,5,6-tetramethyl-BODIPY unit is disclosed, and a versatile way to further functionalize this unit has been developed. The optoelectronic properties of the two dyes were computed by density functional theory modelling (DFT) and characterized through UV-vis spectroscopy and cyclic voltammetry (CV) measurements. Finally, we report preliminary results obtained using these functional dyes as photosensitizers in dyesensitized solar cells (DSSCs).
Oxidative coupling of 1,7,8-unsubstituted BODIPYs: Synthesis and electrochemical and spectroscopic properties
Poirel, Arnaud,De Nicola, Antoinette,Retailleau, Pascal,Ziessel, Raymond
, p. 7512 - 7525 (2012/11/13)
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.
Gas-phase heteroaromatic substitution. 14. Attack of dimethylfluoronium ion on 2- and 3-methyl-pyrroles, -furans, -and thiophenes
Cecchi, Patrizio,Pizzabiocca, Adriano,Renzi, Gabriele,Sparapani, Cinzia,Speranza, Maurizio
, p. 2094 - 2103 (2007/10/02)
The gas-phase methylation of 2- and 3-methyl-pyrroles (2P and 3P), -furans (2F and 3F), and thiophenes (2T and 3T) by (CH3)2F+ ions, from γ-radiolysis of CH3F, has been investigated at pressures ranging from 50 to 760 Torr, in the presence of a thermal radical scavenger (O2) and variable concentrations of an added base (NMe3: 0-10 Torr).The mechanism of the methylation process is discussed and the intrinsic positional selectivity of the (CH3)2F+ ions evaluated in the framework of the Charge and Frontier Orbital Control concept.Owing to the very large energy gap between the LUMO of (CH3)2F+ and the HOMOs of the selected heteroaromatic substrates, their gas-phase methylation is characterized by a distinct affinity of the ionic electrophile toward those substrates positions with the highest net negative charge, i.e., the C3 in 2P (100percent), the C4 in 3P (100percent), the heteroatom of 2F and 3F (>80percent), the C5 of 2T (32percent), and the C2 of 3T (47percent).Analysis of the methylated product distribution from 2F and 3F as a function of the experimental conditions reveals that the interaction of the (CH3)2F+ with the heteroatom of furans gives rise to the reversible formation of two sets of electrostatic adducts, i.e., a "chelate" adduct (III) and a single proton-bonded adduct (IV), the first rapidly evolving to the α-substituted heteroarenium intermediate by proximity effects and the latter slowly rearranging to the chelate structure III.Formation of these categories of electrostatic adducts from furans, which is much less extensive in the case of thiophenes and absent in pyrroles, accounts for the apparent pronounced affinity of gaseous alkylating electrophiles, irrespective of their LUMO energy, for the α carbons of furans. Key words: gas-phase ion chemistry, electrophilic aromatic substitution, radiolysis, dimethylfluoronium ions, methylated heteroarenes.
