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Angewandte Chemie (International Ed. in... Aug 2022My favorite example of science in everyday life is photochemistry, nature's most efficient way to store solar energy … My favorite way to spend a holiday is hiking in...
My favorite example of science in everyday life is photochemistry, nature's most efficient way to store solar energy … My favorite way to spend a holiday is hiking in polar regions far from everyone …" Find out more about Tomáš Slanina in his Introducing … Profile.
Topics: Photochemistry; Solar Energy
PubMed: 35796216
DOI: 10.1002/anie.202208779 -
Molecules (Basel, Switzerland) May 2020The use of light-activated chemical probes to study biological interactions was first discovered in the 1960s, and has since found many applications in studying diseases... (Review)
Review
The use of light-activated chemical probes to study biological interactions was first discovered in the 1960s, and has since found many applications in studying diseases and gaining deeper insight into various cellular mechanisms involving protein-protein, protein-nucleic acid, protein-ligand (drug, probe), and protein-co-factor interactions, among others. This technique, often referred to as photoaffinity labelling, uses radical precursors that react almost instantaneously to yield spatial and temporal information about the nature of the interaction and the interacting partner(s). This review focuses on the recent advances in chemical biology in the use of benzophenones and diazirines, two of the most commonly known light-activatable radical precursors, with a focus on the last three years, and is intended to provide a solid understanding of their chemical and biological principles and their applications.
Topics: Benzophenones; Diazomethane; Photoaffinity Labels; Photochemistry
PubMed: 32414020
DOI: 10.3390/molecules25102285 -
Nature Plants Jul 2018
Topics: Chlorophyll; Photochemistry
PubMed: 29977084
DOI: 10.1038/s41477-018-0208-8 -
Chemical Reviews Jan 2022Geometrical → alkene isomerization is intimately entwined in the historical fabric of organic photochemistry and is enjoying a renaissance (Roth et al. ,... (Review)
Review
Geometrical → alkene isomerization is intimately entwined in the historical fabric of organic photochemistry and is enjoying a renaissance (Roth et al. , 1193-1207). This is a consequence of the fundamental stereochemical importance of -alkenes, juxtaposed with frustrations in thermal reactivity that are rooted in microscopic reversibility. Accessing excited state reactivity paradigms allow this latter obstacle to be circumnavigated by exploiting subtle differences in the photophysical behavior of the substrate and product chromophores: this provides a molecular basis for directionality. While direct irradiation is operationally simple, photosensitization via selective energy transfer enables augmentation of the alkene repertoire to include substrates that are not directly excited by photons. Through sustained innovation, an impressive portfolio of tailored small molecule catalysts with a range of triplet energies are now widely available to facilitate -thermodynamic and thermo-neutral isomerization reactions to generate -alkene fragments. This review is intended to serve as a practical guide covering the geometric isomerization of alkenes enabled by energy transfer catalysis from 2000 to 2020, and as a logical sequel to the excellent treatment by Dugave and Demange (. , 2475-2532). The mechanistic foundations underpinning isomerization selectivity are discussed together with induction models and rationales to explain the counterintuitive directionality of these processes in which very small energy differences distinguish substrate from product. Implications for subsequent stereospecific transformations, application in total synthesis, regioselective polyene isomerization, and spatiotemporal control of pre-existing alkene configuration in a broader sense are discussed.
Topics: Alkenes; Catalysis; Energy Transfer; Isomerism; Photochemistry
PubMed: 34449198
DOI: 10.1021/acs.chemrev.1c00324 -
Angewandte Chemie (International Ed. in... Dec 2022Enzymes have several advantages over conventional catalysts for organic synthesis. Over the last two decades, much effort has been made to further extend the scope of... (Review)
Review
Enzymes have several advantages over conventional catalysts for organic synthesis. Over the last two decades, much effort has been made to further extend the scope of biocatalytic reactions available to synthetic chemists, particularly by expanding the repertoire of enzymes for abiological transformations. In this regard, exciting new developments in the area of photobiocatalysis enable now the introduction of non-natural reactivity in enzymes to solve long-standing synthetic challenges. A recently described example from the Hyster group demonstrates in an unprecedented way how the combination of photochemistry with enzyme catalysis empowers the catalytic asymmetric construction of Csp -Csp bonds with high chemo- and enantioselectivity.
Topics: Stereoisomerism; Catalysis; Biocatalysis; Chemistry Techniques, Synthetic; Photochemistry; Enzymes
PubMed: 36239986
DOI: 10.1002/anie.202214313 -
Environmental Science and Pollution... Dec 2022Mismanagement of obsolete solid waste generates a massive deteriorating effect on the environment. There is a high level of open trash disposal contaminating its...
Mismanagement of obsolete solid waste generates a massive deteriorating effect on the environment. There is a high level of open trash disposal contaminating its neighboring water bodies. This despoliation trash causes an endangerment to the living environment. The waste management act is to hinder harmful effects on human beings, animals, plants, and their natural environment through the principles of waste prevention, waste processing, and waste disposal. Surface-enhanced Raman scattering (SERS) enhances the hazardous chemical sensing of environmental pollutants. To vigorously focus on the leaching of a couple of landfills in groundwater and surface water, an unusual combination of SERS-based poly vinyl thiol and silica-modified silver nanocomposites (PVT/SiO2@Ag NCs) was synthesized. The optical, crystalline, and structural properties of PVT/SiO@Ag NCs were described with UV-visible spectroscopy (UV-Vis), X-ray diffractometer (XRD), transmission electron microscope (TEM), and energy-dispersive X-ray analysis (EDX). The surface plasmon resonance (SPR) is detected at 403 nm from the PVT/SiO@Ag NPs. The average crystallite size of PVT/SiO @ Ag NCs is estimated using the Scherrer formula as 11 nm. The calculated specific surface area (SSA), strains, and dislocation densities demonstrate the improved mechanical properties of the substrate. The well-separated spherical shape of NPs is also observed, and the composition of silica and sulfur element in addition of Ag was confirmed by EDAX. Negatively charged SiO were bound strongly with the SH group and Ag NPs through electrostatic interaction mechanism as S-Ag-O-Si-O-Ag-S. SERS sensitivity is demonstrated by the prepared nanoparticles using an environmentally ignored leachate of municipal solid waste (MSW) and tannery waste (TW) landfill. PVT/SiO@Ag NCs has detected the presence of innards of MSW leachate viz., aromatic hydrocarbon, phenols, phthalates, and pesticide from the groundwater. Furthermore, the TW leachate compositions of benzenes, hydrocarbons, amines, and chromium VI were analytically identified. Also, the leaching of TW leachate was confirmed in the water samples referred. Hence, this study provides a novel SERS sensor of PVT/SiO@Ag NCs in the tile to detect and analyze environmentally ignored organic and inorganic compounds.
Topics: Humans; Solid Waste; Silicon Dioxide; Sulfhydryl Compounds; Photochemistry; Water
PubMed: 35861900
DOI: 10.1007/s11356-022-22058-0 -
Chemistry (Weinheim An Der Bergstrasse,... Mar 2021Photochemistry provides a wide range of alternative reagents that hold potential for use in bimolecular functionalisation of proteins. Here, we report the synthesis and...
Photochemistry provides a wide range of alternative reagents that hold potential for use in bimolecular functionalisation of proteins. Here, we report the synthesis and characterisation of metal ion binding chelates derivatised with disubstituted tetrazoles for the photoradiochemical labelling of monoclonal antibodies (mAbs). The photophysical properties of tetrazoles featuring extended aromatic systems and auxochromic substituents to tune excitation toward longer wavelengths (365 and 395 nm) were studied. Two photoactivatable chelates based on desferrioxamine B (DFO) and the aza-macrocycle NODAGA were functionalised with a tetrazole and developed for protein labelling with Zr, Cu and Ga radionuclides. DFO-tetrazole (1) was assessed by direct conjugation to formulated trastuzumab and subsequent radiolabelling with Zr. Radiochemical studies and cellular-based binding assays demonstrated that the radiotracer remained stable in vitro retained high immunoreactivity. Positron emission tomography (PET) imaging and biodistribution studies were used to measure the tumour specific uptake and pharmacokinetic profile in mice bearing SK-OV-3 xenografts. Experiments demonstrate that tetrazole-based photochemistry is a viable approach for the light-induced synthesis of PET radiotracers.
Topics: Animals; Cell Line, Tumor; Mice; Molecular Imaging; Photochemistry; Positron-Emission Tomography; Tetrazoles; Tissue Distribution; Zirconium
PubMed: 33427351
DOI: 10.1002/chem.202100061 -
Molecules (Basel, Switzerland) Feb 2023One of the challenges in developing practical CO photoconversion catalysts is the design of materials with a low cost, high activity and good stability. In this paper,... (Review)
Review
One of the challenges in developing practical CO photoconversion catalysts is the design of materials with a low cost, high activity and good stability. In this paper, excellent photocatalysts based on TiO, WO, ZnO, CuO and CeO metal oxide materials, which are cost-effective, long-lasting, and easy to fabricate, are evaluated. The characteristics of the nanohybrid catalysts depend greatly on their architecture and design. Thus, we focus on outstanding materials that offer effective and practical solutions. Strategies to improve CO conversion efficiency are summarized, including heterojunction, ion doping, defects, sensitization and morphology control, which can inspire the future improvement in photochemistry. The capacity of CO adsorption is also pivotal, which varies with the morphological and electronic structures. Forms of 0D, 1D, 2D and 3DOM (zero/one/two-dimensional- and three-dimensional-ordered macroporous, respectively) are involved. Particularly, the several advantages of the 3DOM material make it an excellent candidate material for CO conversion. Hence, we explain its preparation method. Based on the discussion, new insights and prospects for designing high-efficient metallic oxide photocatalysts to reduce CO emissions are presented.
Topics: Carbon Dioxide; Adsorption; Electronics; Oxides; Photochemistry
PubMed: 36838641
DOI: 10.3390/molecules28041653 -
Nature Nanotechnology Dec 2016Phototaxis is commonly observed in motile photosynthetic microorganisms. For example, green algae are capable of swimming towards a light source (positive phototaxis) to...
Phototaxis is commonly observed in motile photosynthetic microorganisms. For example, green algae are capable of swimming towards a light source (positive phototaxis) to receive more energy for photosynthesis, or away from a light source (negative phototaxis) to avoid radiation damage or to hide from predators. Recently, with the aim of applying nanoscale machinery to biomedical applications, various inorganic nanomotors based on different propulsion mechanisms have been demonstrated. The only method to control the direction of motion of these self-propelled micro/nanomotors is to incorporate a ferromagnetic material into their structure and use an external magnetic field for steering. Here, we show an artificial microswimmer that can sense and orient to the illumination direction of an external light source. Our microswimmer is a Janus nanotree containing a nanostructured photocathode and photoanode at opposite ends that release cations and anions, respectively, propelling the microswimmer by self-electrophoresis. Using chemical modifications, we can control the zeta potential of the photoanode and program the microswimmer to exhibit either positive or negative phototaxis. Finally, we show that a school of microswimmers mimics the collective phototactic behaviour of green algae in solution.
Topics: Light; Locomotion; Microscopy, Electron, Scanning; Nanowires; Photochemistry; Phototaxis; Surface Properties; Titanium
PubMed: 27749832
DOI: 10.1038/nnano.2016.187 -
Nature Chemistry Jan 2016The self-assembly of chemical entities represents a very attractive way to create a large variety of ordered functional structures and complex matter. Although much...
The self-assembly of chemical entities represents a very attractive way to create a large variety of ordered functional structures and complex matter. Although much effort has been devoted to the preparation of supramolecular nanostructures based on different chemical building blocks, an understanding of the mechanisms at play and the ability to monitor assembly processes and, in turn, control them are often elusive, which precludes a deep and comprehensive control of the final structures. Here the complex supramolecular landscape of a platinum(II) compound is characterized fully and controlled successfully through a combination of supramolecular and photochemical approaches. The supramolecular assemblies comprise two kinetic assemblies and their thermodynamic counterpart. The monitoring of the different emission properties of the aggregates, used as a fingerprint for each species, allows the real-time visualization of the evolving self-assemblies. The control of multiple supramolecular pathways will help the design of complex systems in and out of their thermodynamic equilibrium.
Topics: Biomimetics; Microscopy, Confocal; Microscopy, Fluorescence; Molecular Structure; Nanostructures; Organoplatinum Compounds; Photochemistry; Solvents; Thermodynamics
PubMed: 26673259
DOI: 10.1038/nchem.2383