A computational study on the effect of structural isomerism on the excited state lifetime and redox energetics of archetype iridium photoredox catalyst platforms [Ir(ppy)2(bpy)]+ and Ir(ppy)3.

This study investigates the impact of structural isomerism on the excited state lifetime and redox energetics of heteroleptic [Ir(ppy)2(bpy)]+ and homoleptic Ir(ppy)3 photoredox catalysts using ground-state and time-dependent density functional theory methods. While the ground- and excited-state reduction potentials differ only slightly among the isomers of these complexes, our findings reveal significant variations in the radiative and non-radiative decay rates of the reactivity-controlling triplet 3MLCT states of these closely related species. The observed differences in radiative decay rates could be traced back to variations in the transition dipole moment, vertical energy gaps, and spin-orbit coupling of the isomers.

Investigation of genotoxicity induced by intermediate frequency magnetic field combined with ionizing radiation: In vitro study on human fibroblast cells.

These days, exposure to electromagnetic fields has become omnipresent in modern society. Not only the extremely-low frequency and radiofrequency, but also intermediate frequency (IF) magnetic field (MF) might be absorbed in the human body resulting in an ever-growing concern about their possible health effects. Devices, such as induction cooktops, chargers, compact fluorescent lamps, touchscreens and electric vehicles emit a wide range of intermediate frequency fields.

Photophysics of Molecular Probes for Amyloid-β Detection: Computational Insights into the Roles of Probe Linker and Functional Groups.

In this computational study, density functional theory (DFT) and time-dependent DFT methods (TD-DFT) were employed to study the optical properties of six families of molecules with donor (D), bridge (B), and acceptor (A) fragments that have potential for use as fluorescent molecular probes for the early detection of Alzheimer's disease. After validating our computational method against experimental data, using X-ray and absorption data, the equilibrium geometries and wave functions of the ground and first singlet excited states were systematically studied. Our simulations demonstrate that the S states of these rod-like D-B-A fluorescent probes are twisted intramolecular charge transfer states with a predominant highest occupied molecular orbital-least unoccupied molecular orbital (HOMO-LUMO) character, the former localized primarily at the donor, whereas the latter at the acceptor site.

Probing Alzheimer's pathology: Exploring the next generation of FDDNP analogues for amyloid β detection.

Fluorescent probes are a powerful tool for imaging amyloid β (Aβ) plaques, the hallmark of Alzheimer's disease (AD). Herein, we report the synthesis and comprehensive characterization of 21 novel probes as well as their optical properties and binding affinities to Aβ fibrils. One of these dyes, 1Ae, exhibited several improvements over FDDNP, an established biomarker for Aβ- and Tau-aggregates.

Divalent Titanium via Reductive N-C Coupling of a Ti Nitrido with π-Acids.

The nitrido-ate complex [(PN)Ti(N){μ-K(OEt)}] (1) (PN=(N-(2-PPr-4-methylphenyl)-2,4,6-MeCH) reductively couples CO and isocyanides in the presence of DME or cryptand (Kryptofix222), to form rare, five-coordinate Ti complexes having a linear cumulene motif, [K(L)][(PN)Ti(NCE)] (E=O, L=Kryptofix222, (2); E=NAd, L=3 DME, (3); E=NBu, L=3 DME, (4); E=NAd, L=Kryptofix222, (5)). Oxidation of 2-5 with [Fc][OTf] afforded an isostructural Ti center containing a neutral cumulene, [(PN)Ti(NCE)] (E=O, (6); E=NAd (7), NBu (8)) and characterization by CW X-band EPR spectroscopy, revealed unpaired electron to be metal centric. Moreover, 1e reduction of 6 and 7 in the presence of Kryptofix222cleanly reformed corresponding discrete Ti complexes 2 and 5, which were further characterized by solution magnetization measurements and high-frequency and -field EPR (HFEPR) spectroscopy.