The photophysical properties of a supramolecular donor-acceptor dyad consisting of an oligo(p-phenylenevinylene) unit and a perylene-diimide unit are described. The dyad is created by functionalising the two chromophores with quadruple hydrogen bonding 2-ureido-4[1H]-pyrimidinone units, which provide a high association constant (K approximately 10(8) M-1 in toluene). This feature enabled us to study the time-resolved photoinduced singlet-energy transfer reaction between the two chromophores in dilute solution with transient pump-probe spectroscopy. This energy transfer occurs with a time constant of 5.1 ps.
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Adv Sci (Weinh)
January 2025
Institute of Molecular Science, University of Valencia, c/Catedrático José Beltrán Martínez 2, Paterna, 46980, Valencia, Spain.
Energy transfer processes in nanohybrids are at the focal point of conceptualizing, designing, and realizing novel energy-harvesting systems featuring nanocrystals that absorb photons and transfer their energy unidirectionally to surface-immobilized functional dyes. Importantly, the functionality of these dyes defines the ultimate application. Herein, CsPbBr perovskite nanocrystals (NCs) are interfaced with zinc phthalocyanine (ZnPc) dyes featuring carboxylic acid.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Centre for Biomedical Engineering, Indian Institute of Technology, Delhi 110016, India.
Dexter energy transfer (DET) of triplet electronic states is used to direct energy in photovoltaics, quench reactive singlet oxygen species in biological systems, and generate them in photodynamic therapy. However, the extent to which repeated DET between aromatic residues can lead to triplet energy migration in proteins has not been investigated. Here, we computationally describe DET rates in microtubules, actin filaments and the intermediate filament, vimentin.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
IGM Resins BV, Gompenstraat 49, 5145 RM, Waalwijk, The Netherlands.
A remarkable and unexpected increase in the photopolymerization efficiency of an acrylic resin by a bisacylphosphine oxide photoinitiator was observed when an optical brightener was present in the medium. High values for the maximal rates of photopolymerization were obtained by RT-FTIR at 365 nm under a very low irradiance of 1 mW/cm. Fluorescence studies revealed that the quenching process occurs through singlet-singlet energy transfer between the first singlet excited state of the optical brightener and the ground state photoinitiator.
View Article and Find Full Text PDFJ Am Chem Soc
August 2024
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
Lanthanide-doped nanoparticles (LnNPs) possess unique optical properties and are employed in various optoelectronic and bioimaging applications. One fundamental limitation of LnNPs is their low absorption cross-section. This hurdle can be overcome through surface modification with organic chromophores with large absorption cross-sections.
View Article and Find Full Text PDFDalton Trans
July 2024
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Two novel covalently linked triads containing one 3-pyrrolyl BODIPY unit and two BODIPY units were synthesized over a sequence of steps using -(-formylphenyl)-3-pyrrolyl BODIPY as a key precursor. Both triads were thoroughly characterized and studied by using HRMS, 1D and 2D NMR spectroscopy, X-ray crystallography, absorption, steady-state and time-resolved fluorescence, cyclic voltammetry, and DFT/TD-DFT techniques. X-ray structural analysis of these triads revealed that the dipyrrin units of both -BODIPY and 3-pyrrolyl BODIPY were oriented in the same plane whereas the dipyrrin unit of the α-BODIPY unit was oriented almost perpendicular to that of the 3-pyrrolyl BODIPY unit.
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