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Journal of Hazardous Materials Feb 2021Heterogeneous Fenton catalysts are emerging as excellent materials for applications related to water purification. In this review, recent trends in the synthesis and... (Review)
Review
Heterogeneous Fenton catalysts are emerging as excellent materials for applications related to water purification. In this review, recent trends in the synthesis and application of heterogeneous Fenton catalysts for the abatement of organic pollutants and disinfection of microorganisms are discussed. It is noted that as the complexity of cell wall increases, the resistance level towards various disinfectants increases and it requires either harsh conditions or longer exposure time for the complete disinfection. In case of viruses, enveloped viruses (e.g. SARS-CoV-2) are found to be more susceptible to disinfectants than the non-enveloped viruses. The introduction of plasmonic materials with the Fenton catalysts broadens the visible light absorption efficiency of the hybrid material, and incorporation of semiconductor material improves the rate of regeneration of Fe(II) from Fe(III). A special emphasis is given to the use of Fenton catalysts for antibacterial applications. Composite materials of magnetite and ferrites remain a champion in this area because of their easy separation and reuse, owing to their magnetic properties. Iron minerals supported on clay materials, perovskites, carbon materials, zeolites and metal-organic frameworks (MOFs) dramatically increase the catalytic degradation rate of contaminants by providing high surface area, good mechanical stability, and improved electron transfer. Moreover, insights to the zero-valent iron and its capacity to remove a wide range of organic pollutants, heavy metals and bacterial contamination are also discussed. Real world applications and the role of natural organic matter are summarised. Parameter optimisation (e.g. light source, dosage of catalyst, concentration of HO etc.), sustainable models for the reusability or recyclability of the catalyst and the theoretical understanding and mechanistic aspects of the photo-Fenton process are also explained. Additionally, this review summarises the opportunities and future directions of research in the heterogeneous Fenton catalysis.
Topics: Catalysis; Disinfection; Humic Substances; Hydrogen Peroxide; Iron; Light; Metal-Organic Frameworks; Minerals; Oxidation-Reduction; Photochemistry; Reactive Oxygen Species; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 33069994
DOI: 10.1016/j.jhazmat.2020.124082 -
ACS Chemical Biology Dec 2022The complex network of naturally occurring biological pathways motivates the development of new synthetic molecules to perturb and/or detect these processes for... (Review)
Review
The complex network of naturally occurring biological pathways motivates the development of new synthetic molecules to perturb and/or detect these processes for fundamental research and clinical applications. In this context, photochemical tools have emerged as an approach to control the activity of drug or probe molecules at high temporal and spatial resolutions. Traditional photochemical tools, particularly photolabile protecting groups (photocages) and photoswitches, rely on high-energy UV light that is only applicable to cells or transparent model animals. More recently, such designs have evolved into the visible and near-infrared regions with deeper tissue penetration, enabling photocontrol to study biology in tissue and model animal contexts. This Review highlights recent developments in synthetic far-red and near-infrared photocages and photoswitches and their current and potential applications at the interface of chemistry and biology.
Topics: Animals; Photochemistry; Infrared Rays; Ultraviolet Rays; Biology; Light
PubMed: 34516095
DOI: 10.1021/acschembio.1c00518 -
Photochemistry and Photobiology Jul 2022The direct photolysis of estrone in solvents ranging from water to cyclohexane is reported. The photodegradation is dominated by lumiestrone, an epimer of estrone...
The direct photolysis of estrone in solvents ranging from water to cyclohexane is reported. The photodegradation is dominated by lumiestrone, an epimer of estrone resulting from the inversion of the methyl group at carbon 13, regardless of solvent and photolysis wavelength in the range 254-320 nm. Solvent addition products are also observed in lesser amounts. The photodegradation rate in water is an order of magnitude slower than in nonaqueous solvents. Short wavelength excitation enhances photodegradation. Together, these results suggest complicated photophysics underlie the photochemistry with implications for the remediation of environmental estrogens.
Topics: Estrone; Photochemistry; Photolysis; Solvents; Water
PubMed: 34664279
DOI: 10.1111/php.13542 -
Journal of Inorganic Biochemistry Aug 2020
Topics: Coordination Complexes; Humans; Luminescence; Macromolecular Substances; Nanoparticles; Photochemistry; Physics; Spectroscopy, Near-Infrared
PubMed: 32512347
DOI: 10.1016/j.jinorgbio.2020.111128 -
Molecules (Basel, Switzerland) Nov 2020Since their conception, ionic liquids (ILs) have been investigated for an extensive range of applications including in solvent chemistry, catalysis, and... (Review)
Review
Since their conception, ionic liquids (ILs) have been investigated for an extensive range of applications including in solvent chemistry, catalysis, and electrochemistry. This is due to their designation as designer solvents, whereby the physiochemical properties of an IL can be tuned for specific applications. This has led to significant research activity both by academia and industry from the 1990s, accelerating research in many fields and leading to the filing of numerous patents. However, while ILs have received great interest in the patent literature, only a limited number of processes are known to have been commercialised. This review aims to provide a perspective on the successful commercialisation of IL-based processes, to date, and the advantages and disadvantages associated with the use of ILs in industry.
Topics: Anions; Catalysis; Cations; Chlorine; Dimerization; Electrochemistry; Fluorine; Hydrogen; Industry; Ionic Liquids; Methylation; Models, Chemical; Organic Chemicals; Photochemistry; Solvents; Temperature
PubMed: 33182328
DOI: 10.3390/molecules25215207 -
Molecules (Basel, Switzerland) Jun 2020Boron-containing π-conjugated materials are archetypical candidates for a variety of molecular scale applications. The incorporation of boron into the π-conjugated... (Review)
Review
Boron-containing π-conjugated materials are archetypical candidates for a variety of molecular scale applications. The incorporation of boron into the π-conjugated frameworks significantly modifies the nature of the parent π-conjugated systems. Several novel boron-bridged π-conjugated materials with intriguing structural, photo-physical and electrochemical properties have been reported over the last few years. In this paper, we review the properties and multi-dimensional applications of the boron-bridged fused-ring π-conjugated systems. We critically highlight the properties of π-conjugated N^C-chelate organoboron materials. This is followed by a discussion on the potential applications of the new materials in opto-electronics (O-E) and other areas. Finally, attempts will be made to predict the future direction/outlook for this class of materials.
Topics: Boron Compounds; Chelating Agents; Coordination Complexes; Electronics; Optical Devices; Photochemistry
PubMed: 32517244
DOI: 10.3390/molecules25112645 -
Chemical Society Reviews Sep 2021There has been a significant push in recent years to deploy fundamental knowledge and methods of photochemistry toward biological ends. Photoreactive groups have enabled... (Review)
Review
There has been a significant push in recent years to deploy fundamental knowledge and methods of photochemistry toward biological ends. Photoreactive groups have enabled chemists to activate biological function using the concept of photocaging. By granting spatiotemporal control over protein activation, these photocaging methods are fundamental in understanding biological processes. Peptides and proteins are an important group of photocaging targets that present conceptual and technical challenges, requiring precise chemoselectivity in complex polyfunctional environments. This review focuses on recent advances in photocaging techniques and methodologies, as well as their use in living systems. Photocaging methods include genetic and chemical approaches that require a deep understanding of structure-function relationships based on subtle changes in primary structure. Successful implementation of these ideas can shed light on important spatiotemporal aspects of living systems.
Topics: Biological Phenomena; Peptides; Photochemistry; Proteins
PubMed: 34320043
DOI: 10.1039/d0cs01434f -
Photochemistry and Photobiology Mar 2022The photolysis of vanillin produces a short-lived triplet state where its lifetime is controlled by efficient self-quenching (k ~ 2 × 10 m s ) which also...
The photolysis of vanillin produces a short-lived triplet state where its lifetime is controlled by efficient self-quenching (k ~ 2 × 10 m s ) which also generates radicals. Free radical reactions, including vanillin dimer formation, are responsible for the degradation of vanillin and is accompanied by yellowing of the acetonitrile solutions. Laser flash photolysis studies reveal a triplet absorbing at 390 nm, readily quenched by naphthalenes, conjugated dienes and oxygen. Vanillin is also a good singlet oxygen sensitizer as revealed by its characteristic NIR emission at 1270 nm.
Topics: Benzaldehydes; Photochemistry; Photolysis; Singlet Oxygen
PubMed: 34570372
DOI: 10.1111/php.13520 -
Nature Communications Nov 2022Phytochromes are ubiquitous photoreceptors responsible for sensing light in plants, fungi and bacteria. Their photoactivation is initiated by the photoisomerization of...
Phytochromes are ubiquitous photoreceptors responsible for sensing light in plants, fungi and bacteria. Their photoactivation is initiated by the photoisomerization of the embedded chromophore, triggering large conformational changes in the protein. Despite numerous experimental and computational studies, the role of chromophore-protein interactions in controlling the mechanism and timescale of the process remains elusive. Here, we combine nonadiabatic surface hopping trajectories and adiabatic molecular dynamics simulations to reveal the molecular details of such control for the Deinococcus radiodurans bacteriophytochrome. Our simulations reveal that chromophore photoisomerization proceeds through a hula-twist mechanism whose kinetics is mainly determined by the hydrogen bond of the chromophore with a close-by histidine. The resulting photoproduct relaxes to an early intermediate stabilized by a tyrosine, and finally evolves into a late intermediate, featuring a more disordered binding pocket and a weakening of the aspartate-to-arginine salt-bridge interaction, whose cleavage is essential to interconvert the phytochrome to the active state.
Topics: Phytochrome; Deinococcus; Photochemistry; Kinetics; Hydrogen Bonding; Bacterial Proteins
PubMed: 36369284
DOI: 10.1038/s41467-022-34640-8 -
Photochemical & Photobiological... Jan 2022Cholesta-5,7,9(11)-trien-3β-ol (9,11-dehydroprovitamin D, CTL) is used as a fluorescent probe to track the presence and migration of cholesterol in vivo. CTL is known...
Cholesta-5,7,9(11)-trien-3β-ol (9,11-dehydroprovitamin D, CTL) is used as a fluorescent probe to track the presence and migration of cholesterol in vivo. CTL is known to be photochemically active, but little consideration has been given to the formation efficiency and possible toxicity of its photoproducts. In degassed tetrahydrofuran (THF) solution, we isolated the photoproduct of CTL and of its 25-hydroxy derivative (HOCTL), and X-ray crystal structures were obtained for HOCTL and the photorearrangement product. The X-ray crystal structure and its H NMR spectrum confirm the product structure as a pentacyclic HOCTL isomer. In the presence of air in THF, endoperoxide formation via [2+4] addition of O* across the B ring of CTL or HOCTL becomes the dominant photoreaction. The UV spectrum and decay kinetics of the triplet state of HOCTL, the precursor of O*, are determined by transient absorption spectroscopy. We confirm the proposed structure of the endoperoxide by X-ray crystallography. Kinetics analysis of quantum yields provides rate constants for photophysical and photochemical events.
Topics: Cholesterol; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Photochemistry; Trientine
PubMed: 35000147
DOI: 10.1007/s43630-021-00131-w