Change of Boron Substitution Improves the Lasing Performance of Bodipy Dyes: A Mechanistic Rationalisation

Abstract

Bodipy laser dyes are highly efficient but degrade rapidly in solution by reacting with in situ generated singlet oxygen ((1)O(2)). To increase the lasing lifetimes of these dyes, we have designed and synthesised two different congeners of the widely studied Pyrromethene 567 (PM567) by substitution at the boron centre and/or at both the boron centre and the meso position. The two new dyes showed high lasing efficiencies with increased photostability. The results of theoretical and pulse radiolysis studies revealed that the substitution at the boron centre reduced the (1)O(2) generation capacity of these dyes as well as their rate of reaction with (1)O(2), thereby enhancing their lifetimes even under lasing conditions.

N‐BODIPYs Come into Play: Smart Dyes for Photonic Materials

“…This ample reactivity allows the derivatization of BODIPYs at their dipyrrin moieties with a great variety of pendant functional groups. However, less synthetic diversity is found when directly functionalizing BODIPYs at boron (red in Figure ), although such functionalization allows the facile preparation of dyes with enhanced photostability for lasing, with improved water solubility for biological applications, with boosted energy‐transfer processes for efficient light collection, or with enhanced chiral perturbation enabling circularly polarized luminescence, among other valuable properties.…”

“…Thus, the absence of fluorine atoms significantly increases the electron density at the boron center, lowering its Lewis acidity and diminishing its capability to be chelated by the dipyrrin moiety. This drawback has been solved in stabilized C ‐ and O ‐BODIPYs by using sufficiently electron‐poor C ‐ and O ‐moieties, such as aryl, alkenyl, alkynyl, aryloxyl, or acyloxyl units, even bearing additional electron‐withdrawing groups in some cases …”

“…[6,8,[11][12][13][14][15] These transformations usually involve the BODIPY dipyrrinm oiety and well-established chemical reactions, such as nucleophilic and electrophilic aromatic substitutions, metal-catalyzed cross-couplings or enol-like condensations, among others (blue in Figure 1). [16][17][18][19][20] This ample reactivity allows the derivatization of BODIPYs at their dipyrrin moieties with ag reat variety of pendant functional groups.However, less synthetic diversity is found when directly functionalizing BODIPYsa tb oron [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] (red in Figure 1), although such functionalizationa llows the facile preparation of dyes with enhancedp hotostabilityf or lasing, [21][22][23][24] with improved water solubilityf or biological applications, [25][26][27] with boostede nergytransfer processes for efficient light collection, [19,[28][29][30][31]33] or with enhanced chiral perturbation enabling circularly polarized luminescen...…”

Syntheses and photodynamic activity of some glucose-conjugated BODIPY dyes

“…Spin-coupling to heavy atoms (the ''heavy atom effect'') that ensures good intersystem crossing (ISC) rates is often used to augment generation of the cytotoxic ROS. However, the BODIPY derivatives are well-known to generate copious amount of ROS, especially 1 O 2 that also leads to their oxidative degradation [34,37]. Hence, we did not address this issue.…”

“…For the past few years, we are actively pursuing research in chemistry and applications of the BODIPYs [34][35][36][37][38]. The aim of the present study was to formulate some new glycosylated BODIPYs that can be easily synthesized, are bioavailable, and show good photosensitization to the target cells.…”