Pyrene Functionalized Norbornadiene-Quadricyclane Fluorescent Photoswitches: Characterization of their Spectral Properties and Application in Imaging of Amyloid Beta Plaques.

This study presents the synthesis and characterization of two fluorescent norbornadiene (NBD) photoswitches, each incorporating two conjugated pyrene units. Expanding on the limited repertoire of reported photoswitchable fluorescent NBDs, we explore their properties with a focus on applications in bioimaging of amyloid beta (Aβ) plaques. While the fluorescence emission of the NBD decreases upon photoisomerization, aligning with what has been previously reported, for the first time we observed luminescence after irradiation of the quadricyclane (QC) isomer.

Bulky Substituents Promote Triplet-Triplet Annihilation Over Triplet Excimer Formation in Naphthalene Derivatives.

Visible-to-ultraviolet (UV) triplet-triplet annihilation photochemical upconversion (TTA-UC) has gained a lot of attention recently due to its potential for driving demanding high-energy photoreactions using low-intensity visible light. The efficiency of this process has rapidly improved in the past few years, in part thanks to the recently discovered annihilator compound 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (N-2TIPS). Despite its beneficial TTA-UC characteristics, the success of N-2TIPS in this context is not yet fully understood.

Triplet States of Cyanostar and Its Anion Complexes.

The design of advanced optical materials based on triplet states requires knowledge of the triplet energies of the molecular building blocks. To this end, we report the triplet energy of cyanostar () macrocycles, which are the key structure-directing units of small-molecule ionic isolation lattices (SMILES) that have emerged as programmable optical materials. Cyanostar is a cyclic pentamer of covalently linked cyanostilbene units that form π-stacked dimers when binding anions as 2:1 complexes.

Best practice in determining key photophysical parameters in triplet-triplet annihilation photon upconversion.

Triplet-triplet annihilation photon upconversion (TTA-UC) is a process in which low-energy light is transformed into light of higher energy. During the last two decades, it has gained increasing attention due to its potential in, e.g.

Approaching the Spin-Statistical Limit in Visible-to-Ultraviolet Photon Upconversion.

Triplet-triplet annihilation photon upconversion (TTA-UC) is a process in which triplet excitons combine to form emissive singlets and holds great promise in biological applications and for improving the spectral match in solar energy conversion. While high TTA-UC quantum yields have been reported for, for example, red-to-green TTA-UC systems, there are only a few examples of visible-to-ultraviolet (UV) transformations in which the quantum yield reaches 10%. In this study, we investigate the performance of six annihilators when paired with the sensitizer 2,3,5,6-tetra(9-carbazol-9-yl)benzonitrile (4CzBN), a purely organic compound that exhibits thermally activated delayed fluorescence.

Diphenylanthracene Dimers for Triplet-Triplet Annihilation Photon Upconversion: Mechanistic Insights for Intramolecular Pathways and the Importance of Molecular Geometry.

Novel approaches to modify the spectral output of the sun have seen a surge in interest recently, with triplet-triplet annihilation driven photon upconversion (TTA-UC) gaining widespread recognition due to its ability to function under low-intensity, noncoherent light. Herein, four diphenylanthracene (DPA) dimers are investigated to explore how the structure of these dimers affects upconversion efficiency. Also, the mechanism responsible for intramolecular upconversion is elucidated.

Filter function of graphene oxide: Trapping perfluorinated molecules.

We need clean drinking water, but current water purification methods are not always sufficient. This study examines the binding and binding mechanisms when graphene oxide is used as a filter material for removing perfluorinated substances and trihalomethanes. We use density functional theory calculations to examine the binding of the harmful molecules on graphene oxide.