A series of unsymmetrically substituted BODIPY dyes featuring fused benzo- or naphtho-fragments on one pyrrolic unit were synthesized from the corresponding pyrrolic precursors. The synthetic route was optimized using a modular approach based on the condensation of formylpyrroles with alkylpyrroles, enabling the identification of precursor combinations that minimize byproduct formation and improve preparative yields. The resulting benzo- and naphtho-fused BODIPYs display intense fluorescence in the red region, with emission maxima spanning 590–680 nm and fluorescence quantum yields ranging from 0.27 to 0.84. Their two-photon absorption (2PA) properties were studied both experimentally and computationally. An increase in the two-photon absorption cross-section with an increase in the size of the π-conjugated system was observed, reaching 80 GM for the naphthoBODIPY derivative. These findings demonstrate the potential of π-extended BODIPY scaffolds as NIR-active fluorophores with enhanced nonlinear optical properties.
Out in @JOC_OL
#JOC: Synthesis and Optical Properties of Unsymmetric Aromatically π-Extended #BODIPY. Great collaboration with #MikhailFilatov @TUDubChemBPharm
@TCD_Chemistry
😀 pubs.acs.org/doi/full/10.... plus #sciart cover picture 🎨. Funded by @researchireland.ie
![Bimanes, a class of molecules based on the 1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione scaffold, were first introduced by E. M. Kosower in 1978. In this study, we report the topochemical cycloaddition of diethyl 2,6-dichloro-1,7-dioxo-1H,7H-pyrazolo[1,2-a]pyrazole-3,5-dicarboxylate (Cl2B), initiated by visible light. Crystal structure analysis confirmed that the reactive double bonds are parallel and coplanar, in line with the Schmidt criteria for topochemical cycloaddition. Additionally, two other bimane derivatives with different substitution patterns were synthesized and investigated. Our findings suggest that functionalizing bimanes to redshift their absorption maxima into the visible-light spectrum provides a promising strategy for synthesizing substituted cyclobutanes without the need for ultraviolet irradiation.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:ls54voiihm3bxde2dkgrxbm3/bafkreidduymtzhb44xcfbfd46fwrtmmzmgmj7u6dbks42otca4k5xfa37i)