Structural Changes in the BODIPY Dye PM567 Enhancing the Laser Action in Liquid and Solid Media

Abstract

In the search for more efficient and photostable solid‐state dye lasers, newly synthesized analogs of the borondipyrromethene (BODIPY) dye PM567, bearing the polymerizable methacryloyloxypropyl group at position 2 (PMoMA) or at positions 2 and 6 (PDiMA), have been studied in the form of solid copolymers with methyl methacrylate (MMA). The parent dye PM567, as well as the model analogs bearing the acetoxypropyl group in the same positions, PMoAc and PDiAc, respectively, have been also studied both in liquid solvents and in solid poly(MMA) (PMMA) solution. Although in liquid solution PMoAc and PDiAc have the same photophysical properties as PM567, PDiAc exhibited a photostability up to 10 times higher than that of PM567 in ethanol under 310 nm‐irradiation. The possible stabilization factors of PDiAc have been analyzed and discussed on the basis of the redox potentials, the ability for singlet molecular oxygen [O2(1Δg)] generation, the reactivity with O2(1Δg), and quantum mechanical calculations. Both PMoAc and PDiAc, pumped transversally at 532 nm, lased in liquid solution with a high (up to 58 %), near solvent‐independent efficiency. This enhanced photostabilization has been also observed in solid polymeric and copolymeric media. While the solid solution of the model dye PDiAc in PMMA showed a lasing efficiency of 33 %, with a decrease in the laser output of ca. 50 % after 60 000 pump pulses (10 Hz repetition rate) in the same position of the sample, the solid copolymer with the double bonded chromophore, COP(PDiMA‐MMA), showed lasing efficiencies of up to 37 %, and no sign of degradation in the laser output after 100 000 similar pump pulses. Even under the more demanding repetition rate of 30 Hz, the laser emission from this material remained at 67 % of its initial laser output after 400 000 pump pulses, which is the highest laser photostability achieved to date for solid‐state lasers based on organic polymeric materials doped with laser dyes. This result indicates that the double covalent linkage of the BODIPY chromophore to a PMMA polymeric matrix is even more efficient than the simple linkage, for its photostabilization under laser operation.

Highly efficient and photostable photonic materials from diiodinated BODIPY laser dyes

“…Perylene Red (5 × 10 4 M) lases at 614 nm with an efficiency of 26% maintaining 70% of its initial emission after 100000 pump pulses. Laser performances exhibited by 1 -3 are significantly more than those recorded here for the common commercially available BDP dyes (PM567, PM597, and PM650) and their 8-alkyl, 8-phenyl, 8-polyphenylene, 2,6-alkyl or 3-styryl analogues [26,[28][29][30][38][39][40], pumped under identical experimental conditions. For instance, the laser efficiencies recorded for PM567, PM597 and PM650 in ethyl acetate solutions are 48%, 58% and 20%, respectively, but, with low photostabilities compared with those exhibited by our BDP derivatives, since the commercial BDP dyes lost their initial emission after just 50000, 80000 and 20000 pump pulses, respectively.…”

Lasing in Self-Assembled Organic Nanowires Based on Aggregation-Induced Emission of BODIPY

“…The fluorescence of BPr in CH 3 CN solution remains reasonably stable even at an excitation intensity of 500 μJ/cm 2 (Figure S12a). − Likewise, the emission of BEs is stable in solution, indicating the photostability under high excitation conditions. Moreover, with the help of external cavity conditions (Figure S12b), BEs in solution exhibits the lasing behavior with a strong superlinearity (Figure S12c) and noticeably reduced bandwidth (Figure S12d), − despite the low quantum yield in solution.…”

“… − Likewise, the emission of BEs is stable in solution, indicating the photostability under high excitation conditions. Moreover, with the help of external cavity conditions (Figure S12b), BEs in solution exhibits the lasing behavior with a strong superlinearity (Figure S12c) and noticeably reduced bandwidth (Figure S12d), − despite the low quantum yield in solution. Therefore, the reduced emission intensities of nanowires are proposed to result from the disintegration of the self-assembled aggregates at high excitation intensities, given that the dissipated thermal energy would disturb the intermolecular interactions.…”

New BODIPY chromophores bound to polyhedral oligomeric silsesquioxanes (POSS) with improved thermo- and photostability

“…Possible reactions between the POSS unit and O 2 ( 1 D g ) were ruled out because PM567 alone or an equimolar mixture of PM567 and POSS( i Bu) 8 showed the same k r value. 16 The results indicated that the new hybrid dyes showed lower k r values than PM567, i.e. they react with O 2 ( 1 D g ) at a lower rate than the parent dye, although the tendency is not the same as that observed in the respective F d values.…”