A series of mono‐ to hexachlorinated BODIPY dyes have been prepared in good to excellent yields through the use of N‐chlorosuccinimide as an inexpensive halogenating reagent. This library of chlorinated dyes allowed analysis in detail, from the experimental and theoretical points of view, of the dependency of the photophysical and optical properties of the dyes on the number and positions of the chlorine substituents on their BODIPY cores. Quantum mechanical calculations predict the regioselectivity of the halogenation reaction and explain why some positions are less prone to chlorination. The new chlorinated BODIPYs exhibit enhanced laser action with respect to their non‐halogenated analogues, both in liquid solution and in the solid phase. In addition, chlorination is a facile and essentially costless protocol for overcoming important shortcomings exhibited by commercially available BODIPYs, which should favor their practical applications in optical and sensing fields.

No abstract

We establish an efficient strategy to optimize the performance of dye-doped host materials consisting of analyzing in a systematic way the dependence of their Amplified Spontaneous Emission (ASE) efficiency and photostability on the composition and structure of the matrices, selected to specifically avoid the thermal and/or chemical (photooxidation) processes, main mechanisms of dye photodegradation. For this study, a number of experimental polyimides have been chosen as a host matrix and their behavior has been compared with that of poly(methyl methacrylate) (PMMA). We correlate the optical properties with the oxygen permeation and thermal properties of the different polymeric hosts doped with perylene dyes to deepen the understanding of the photodegradation mechanism predominant in these dyes and to minimize its influence. We demonstrate high efficiency and photostable ASE from waveguides based on polymeric materials doped with Perylene Orange (PO), Perylene Red (PR), and mixtures of both. This enhancement in the optical properties allows reaching high gain and long-lasting distributed feedback (DFB) laser emission based on PO doped polymer matrices, even when operating in an unoptimised resonator.

New BODIPY dyes with two 4-formylphenyl, 4-(2,2-dimethoxycarbonylvinyl)phenyl and 4-(2,2-dicyanovinyl)phenyl groups at the 3-and 5-positions have been successfully designed and synthesized via palladium-catalyzed coupling reaction or Knoevenagel-type condensations. Structural modification of the BODIPY core via conjugation-extending residues significantly affects the spectroscopy and photophysical properties of the BODIPY fluorophore. These substituents cause the largest bathochromic shift in both absorption and emission spectra, which are shifted toward the red compared to its 4-phenylsubstituted analogue. Additionally, the fluorescence quantum yields and the Stokes shifts are also significantly higher than the corresponding phenyl-substituted dye. New BODIPY dyes have a high laser photostability, superior to that of commercial dyes with laser emission in the same spectral region, such as Perylene Red and Rhodamine 640. The substitution introduced in these derivatives allows to obtain tunable laser emission with a bandwidth of 0.15 cm À1 and a tuning range of up to 50 nm.So with these three dyes it is possible to cover the spectral range 590-680 nm in a continuous way and with stable laser emission and small linewidth.

Scheme 2 . Synthetic routes of derivatives 6 , 8 , and 15 from parent dye PM597. Scheme 1 . Synthetic routes of derivatives 2 , 7 , and 11 from parent dye PM567.