1198404-10-2Relevant academic research and scientific papers
Energy transfer by way of an exciplex intermediate in flexible boron dipyrromethene-based allosteric architectures
Mula, Soumyaditya,Elliott, Kristopher,Harriman, Anthony,Ziessel, Raymond
, p. 10515 - 10522 (2010)
We have designed and synthesized a series of modular, dual-color dyes comprising a conventional boron dipyrromethene (Bodipy) dye, as a yellow emitter, and a Bodipy dye possessing extended conjugation that functions as a red emitter. A flexible tether of variable length, built from ethylene glycol residues, connects the terminal dyes. A critical design element of this type of dyad relates to a secondary amine linkage interposed between the conventional Bodipy and the tether. Cyclic voltammetry shows both Bodipy dyes to be electroactive and indicates that the secondary amine is quite easily oxidized. The ensuing fluorescence quenching is best explained in terms of the rapid formation of an intermediate charge-transfer state. In fact, exciplex-type emission is observed in weakly polar solvents and over a critical temperature range. In the dual-color dyes, direct excitation of the yellow emitter results in the appearance of red fluorescence, indicating that the exciplex is likely involved in the energy-transfer event, and provides for a virtual Stokes shift of 5000 cm-1. Replacing the red emitter with a higher energy absorber (namely, pyrene) facilitates the collection of near-UV light and extends the virtual Stokes shift to 8000 cm-1. Modulation of the efficacy of intramolecular energy transfer is achieved by preorganization of the connector in the presence of certain cations. This latter behavior, which is fully reversible, corresponds to an artificial allosteric effect.
Dual Bodipy fluorophores linked by polyethyleneglycol spacers
Mula, Soumyaditya,Ulrich, Gilles,Ziessel, Raymond
scheme or table, p. 6383 - 6388 (2010/02/28)
Several Bodipy dyes were synthesized with various substituents designed to potentially interact with adventurous cations including protons. Among the different synthetic strategies, protection of the amino group by a BOC appears efficient for the substitu
