Donor-acceptor dyads are promising materials for improving triplet-sensitized photon upconversion due to faster intramolecular energy transfer (ET), which unfortunately competes with charge transfer (CT) dynamics. To circumvent the issue associated with CT, we propose a novel purely organic donor-acceptor dyad, where the CT character is confined within the donor moiety. In this work, we report the synthesis and characterization of a stable organic radical donor-triplet acceptor dyad () consisting of the acceptor perylene () linked to the donor (4--carbazolyl-2,6-dichlorophenyl)-bis(2,4,6-trichlorophenyl)methyl radical ().
View Article and Find Full Text PDFPoly-aromatic systems that contain quinodimethyl (QDM) units are appealing for several photonic and spintronic applications owing to the unique electronic structure, aromaticity, and spin state(s) of the QDM ring. Herein, we report the synthesis and characterization of novel QDM-based chromophores 1-3, which exhibit unique photo-excited behavior and aromaticity. Extending the aromatic core with a biphenyl/phenanthryl- and a pyrrolo-fragment led to reducing the optoelectronic bandgap and modulating the photophysics QDM 1-3.
View Article and Find Full Text PDFWe report the synthesis and photophysical characterization of novel halogenated dipyrrolonaphthyridine-diones (X -DPNDs, X = Cl, Br, and I), as candidates for photodynamic therapy (PDT) application. Apart from the heavy atom-induced spin-orbit coupling (SOC) dynamics in the investigated X -DPNDs, it was found that the position of the halogen atom (relative to the nitrogen of the pyrrole ring) also influenced the triplet excited state behavior. Interestingly, the faster/efficiency sensitization of O to O using X -DPND correlates with the rate of triplet population, k >1.
View Article and Find Full Text PDFPhotocatalytic polymers offer an alternative to prevailing organometallics and nanomaterials, and they may benefit from polymer-mediated catalytic and material enhancements. MPC-1, a polymer photoredox catalyst reported herein, exhibits enhanced catalytic activity arising from charge transfer states (CTSs) between its two chromophores. Oligomeric and polymeric MPC-1 preparations both promote efficient hydrodehalogenation of α-halocarbonyl compounds while exhibiting different solubility properties.
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