A5087026021- Electrocatalysts for Energy Conversion
- Advanced Photocatalysis Techniques
- CO2 Reduction Techniques and Catalysts
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Metalloenzymes and iron-sulfur proteins
- Luminescence and Fluorescent Materials
- Porphyrin and Phthalocyanine Chemistry
- Photochemistry and Electron Transfer Studies
- Radical Photochemical Reactions
- Metal complexes synthesis and properties
- Advanced Nanomaterials in Catalysis
- Polyoxometalates: Synthesis and Applications
- Electrochemical Analysis and Applications
- Organic Light-Emitting Diodes Research
- Nanocluster Synthesis and Applications
- Spectroscopy and Quantum Chemical Studies
- Molecular Sensors and Ion Detection
- Nanoplatforms for cancer theranostics
- Photochromic and Fluorescence Chemistry
- Molecular Junctions and Nanostructures
- Lanthanide and Transition Metal Complexes
- Advanced biosensing and bioanalysis techniques
- Photoreceptor and optogenetics research
- Quantum Dots Synthesis And Properties
Helmholtz Institute Jena
2021-2025
Friedrich Schiller University Jena
2021-2025
Leibniz Institute of Photonic Technology
2021-2025
Leibniz Institute of Surface Engineering
2025
Albert Einstein College of Medicine
2024
Unequivocal assignment of rate-limiting steps in supramolecular photocatalysts is utmost importance to rationally optimize photocatalytic activity. By spectroscopic and catalytic analysis a series three structurally similar [(tbbpy)2Ru-BL-Rh(Cp*)Cl]3+ just differing the central part (alkynyl, triazole or phenazine) bridging ligand (BL) we are able derive design strategies for improved activity this class compounds (tbbpy = 4,4´-tert-butyl-2,2´-bipyridine, Cp* pentamethylcyclopentadienyl)....
Rhodamine fluorophores are setting benchmarks in fluorescence microscopy. Herein, we report the deuterium (d12) congeners of tetramethyl(silicon)rhodamine, obtained by isotopic labelling four methyl groups, show improved photophysical parameters (
Molecular transition metal chromophores play a central role in light harvesting and energy conversion. Recently, earth-abundant transition-metal-based have begun to challenge the dominance of platinum group complexes this area. However, development new with optimized photophysical properties is still limited by lack synthetic methods, especially respect heteroleptic functional ligands. Here, we demonstrate facile efficient method for combination strong-field carbenes 2,2'-bibenzimidazole...
Azobenzene molecular switches are widely used to photocontrol material properties, and biological activity in cell culture, via photoisomerisation between E Z isomers. However, because population photoswitching is incomplete, their dynamic range of property control often small; they cannot be operated with red/NIR light, usually not applicable deep tissue. Here, we demonstrate a general method for efficient single-photon azobenzenes, glutamate receptor activity, at >700 nm live We use...
Identification of rate determining steps concerning catalyst activation and catalytic turnover is key to optimize molecular photocatalysts. In this contribution, femtosecond transient absorption spectroscopy upon variation temperature ionic strength yields new insights into the light-driven reactivity benchmark photocatalyst, RutpphzRhCp*.
The design and development of particulate photocatalysts has been an attractive strategy to incorporate earth‐abundant metal ions water splitting devices. Herein, we synthesized CoFe‐Prussian blue (PB) coated ZnO origami core‐shell nanostructures (PB@ZnO) with different mass ratio PB components investigated their photocatalytic oxidation activities in the presence electron scavenger. Photocatalytic experiments reveal that integration on boosts oxygen evolution rate by a factor ~2.4 compared...
Three new cobalt complexes of the general formula [Co(II)(L)(CH3CN) ]2+, where L is one three pentadentate nitrogen‐donor ligands based on N4Py framework, have been synthesized and characterized. The capacity to effect photocatalytic proton reduction has examined. Their activities in presence [Ru(bpy)3]2+, acting as a photosensitizer, ascorbic acid, sacrificial electron donor, were screened water/acetonitrile mixture. photochemical mechanism, revealed by nanosecond time‐resolved transient...
While Pt(II) complexes containing doubly cyclometalated ligands as tridentate luminophores are well studied, the synthetic accessibility of their Pd(II) counterparts was lacking for a long time. Inspired by recent report on synthesis [Pd(dpp)(PPh3)] involving C∧N∧C coordination mode (with dpp2– = 2,6-di(phenid-2-yl)pyridine) and following our own work closely related Pt(II)-based compounds, we produced series [Pd(dpp)(PnPh3)] (Pn P, As, Sb) optimizing procedure exploring reactivity in...
The main obstacle in replacing well-established precious ruthenium photosensitizers with earth-abundant iron analogs is the short excited state lifetimes of metal-to-ligand charge transfer (MLCT) states due to relatively weak octahedral field splitting and relaxation via metal-centered (MC) states. In this study, we address issue lifetime by using pentacyanoferrate(II) complexes combat facile photodissociation utilizing positively charged pyrazinium or bipyridinium ligands. We utilize...
Supramolecular photocatalysts consisting of photosensitizer (PS), bridging ligand (BL), and catalytic center (CAT) have garnered significant attention in solar fuel applications. In this study, the photophysics photocatalytic properties two Ru(II)-based dinuclear complexes, specifically [(tbbpy)2Ru(p(Ph)np)Rh(Cp*)Cl]3+ (n = 0, 1; Ru(pp)Rh for n 0 or Ru(p(Ph)p)Rh tbbpy 4,4'-di-tert-butyl-2,2'-bipyridine, Cp* pentamethylcyclopentadienyl, Ph phenyl, p 1,10-phenanthroline), are investigated....
With the aim of developing photostable near-infrared cell imaging probes, a convenient route to synthesis heteroleptic OsII complexes containing Os(TAP)2 fragment is reported. This method was used synthesize dinuclear complex, [{Os(TAP)2}2tpphz]4+ (where tpphz = tetrapyrido[3,2-a:2′,3′-c:3″,2′′-h:2‴,3′′′-j]phenazine and TAP 1,4,5,8- tetraazaphenanthrene). Using combination resonance Raman time-resolved absorption spectroscopy, as well computational studies, excited state dynamics new complex...
BODIPY heterochromophores, asymmetrically substituted with perylene and/or iodine at the 2 and 6 positions were prepared investigated as sensitizers for triplet-triplet annihilation up conversion (TTA-UC). Single-crystal X-ray crystallographic analyses show that torsion angle between units lie 73.54 74.51, though they are not orthogonal. Both compounds intense, charge transfer absorption emission profiles, confirmed by resonance Raman spectroscopy consistent DFT calculations. The quantum...
We report on a photocatalytic setup that utilizes the organic photosensitizer (PS) diiodo-BODIPY and non-precious-metal-based hydrogen evolution reaction (HER) catalyst (NH4)2[Mo3S13] together with polyampholytic unimolecular matrix poly(dehydroalanine)-graft-poly(ethylene glycol) (PDha-g-PEG) in aqueous media. The system shows exceptionally high performance turnover numbers (TON > 7300) frequencies (TOF 450 h-1) are typical for noble-metal-containing systems. Excited-state absorption...
Abstract Optoacoustic (or photoacoustic) imaging promises micron‐resolution noninvasive bioimaging with much deeper penetration (>cm) than fluorescence. However, optoacoustic of enzyme activity would require loud, photostable, NIR‐absorbing molecular contrast agents, which remain unknown. Most organic agents are repurposed fluorophores, severe shortcomings photoinstability or phototoxicity under imaging, as consequences their slow S 1 →S 0 electronic relaxation. We now report that known...
In recent years, dyads in which molecular donor and acceptor moieties are chemically linked by a bridging ligand have emerged as attractive systems for light-driven catalysis. Their modular structure, controllable donor-acceptor distance, their ability to undergo charge transfer, is not limited diffusion, render such promising charge-transfer reactions redox Copper-catalyzed alkyne azide cycloaddition (CuAAC) particularly popular synthetic strategy coupling moieties. This CLICK chemistry...
Abstract This study employs TLD1433, a Ru II ‐based photodynamic therapy (PDT) agent in human clinical trials, as benchmark to establish protocols for studying the excited‐state dynamics of photosensitizers (PSs) cellulo , local environment provided by cancer cells. Very little is known about properties any PS live cells, and it terra incognita . contribution targets general problem phototherapy, which how interrogate light‐triggered, function‐determining processes PSs relevant biological...
Excited states are the key species in photocatalysis, while critical parameters that govern their applications (i) excitation energy, (ii) accessibility, and (iii) lifetime. However, molecular transition metal-based photosensitizers, there is a design tension between creation of long-lived excited (triplet), e.g., metal-to-ligand charge transfer (3MLCT) population such states. Long-lived triplet have low spin-orbit coupling (SOC) hence low. Thus, state can be populated but inefficiently. If...
Aryl chlorides as substrates for arylations present a particular challenge photoredox catalytic activation due to their strong C(sp2 )-Cl bond and reduction potential. Electron-rich N-phenylphenothiazines, organophotoredox catalysts, are capable of cleaving aryl simply by photoinduced electron transfer without the need an additional electrochemical setup or any other advanced photocatalysis technique. Due extremely potential in excited state N-phenylphenothiazines substrate scope is high...
Inspired by the active center of natural [FeFe] hydrogenases, we designed a compact and precious metal-free photosensitizer-catalyst dyad (PS-CAT) for photocatalytic hydrogen evolution under visible light irradiation. PS-CAT represents prototype comprising π-conjugated oligothiophenes as absorbers. its interaction with sacrificial donor 1,3-dimethyl-2-phenylbenzimidazoline were studied steady-state time-resolved spectroscopy coupled electrochemical techniques light-driven investigations....
Abstract Soft matter integration of photosensitizers and catalysts provides promising solutions to developing sustainable materials for energy conversion. Particularly, hydrogels bring unique benefits, such as spatial control 3D‐accessibility molecular units, well recyclability. Herein, the preparation polyampholyte based on poly(dehydroalanine) (PDha) is reported. Chemically crosslinked PDha with bis‐epoxy poly(ethylene glycol) leads a transparent, self‐supporting hydrogel. Due ionizable...