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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 -
Angewandte Chemie (International Ed. in... Mar 2018Biological processes are naturally regulated with high spatial and temporal control, as is perhaps most evident in metazoan embryogenesis. Chemical tools have been... (Review)
Review
Biological processes are naturally regulated with high spatial and temporal control, as is perhaps most evident in metazoan embryogenesis. Chemical tools have been extensively utilized in cell and developmental biology to investigate cellular processes, and conditional control methods have expanded applications of these technologies toward resolving complex biological questions. Light represents an excellent external trigger since it can be controlled with very high spatial and temporal precision. To this end, several optically regulated tools have been developed and applied to living systems. In this review we discuss recent developments of optochemical tools, including small molecules, peptides, proteins, and nucleic acids that can be irreversibly or reversibly controlled through light irradiation, with a focus on applications in cells and animals.
Topics: Animals; Cell Physiological Phenomena; Drug Discovery; Humans; Light; Molecular Docking Simulation; Nucleic Acids; Optogenetics; Peptides; Photochemical Processes; Photochemistry; Protein Multimerization; Proteins; Small Molecule Libraries
PubMed: 28521066
DOI: 10.1002/anie.201700171 -
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 -
ACS Central Science Aug 2020As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern... (Review)
Review
As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern synthetic innovation. In this regard, photochemistry and electrochemistry-both considered as niche fields for decades-have seen an explosive renewal of interest in recent years and gradually have become a cornerstone of organic chemistry. In this Outlook article, we examine the current state-of-the-art in the areas of electrochemistry and photochemistry, as well as the nascent area of electrophotochemistry. These techniques employ external stimuli to activate organic molecules and imbue privileged control of reaction progress and selectivity that is challenging to traditional chemical methods. Thus, they provide alternative entries to known and new reactive intermediates and enable distinct synthetic strategies that were previously unimaginable. Of the many hallmarks, electro- and photochemistry are often classified as "green" technologies, promoting organic reactions under mild conditions without the necessity for potent and wasteful oxidants and reductants. This Outlook reviews the most recent growth of these fields with special emphasis on conceptual advances that have given rise to enhanced accessibility to the tools of the modern chemical trade.
PubMed: 32875074
DOI: 10.1021/acscentsci.0c00549 -
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 -
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 -
Molecules (Basel, Switzerland) Jan 2020The last decade has witnessed a remarkable development towards improved and new photochemical transformations in response to greener and more sustainable chemical... (Review)
Review
The last decade has witnessed a remarkable development towards improved and new photochemical transformations in response to greener and more sustainable chemical synthesis needs. Additionally, the availability of modern continuous flow reactors has enabled widespread applications in view of more streamlined and custom designed flow processes. In this focused review article, we wish to evaluate the standing of the field of continuous flow photochemistry with a specific emphasis on the generation of bioactive entities, including natural products, drugs and their precursors. To this end we highlight key developments in this field that have contributed to the progress achieved to date. Dedicated sections present the variety of suitable reactor designs and set-ups available; a short discussion on the relevance of greener and more sustainable approaches; and selected key applications in the area of bioactive structures. A final section outlines remaining challenges and areas that will benefit from further developments in this fast-moving area. It is hoped that this report provides a valuable update on this important field of synthetic chemistry which may fuel developments in the future.
Topics: Biological Products; Humans; Photochemical Processes; Photochemistry
PubMed: 31952244
DOI: 10.3390/molecules25020356 -
Angewandte Chemie (International Ed. in... Jan 2021Amino acids (AAs) are key structural motifs with widespread applications in organic synthesis, biochemistry, and material sciences. Recently, with the development of... (Review)
Review
Amino acids (AAs) are key structural motifs with widespread applications in organic synthesis, biochemistry, and material sciences. Recently, with the development of milder and more versatile radical-based procedures, the use of strategies relying on radical chemistry for the synthesis and modification of AAs has gained increased attention, as they allow rapid access to libraries of novel unnatural AAs containing a wide range of structural motifs. In this Minireview, we provide a broad overview of the advancements made in this field during the last decade, focusing on methods for the de novo synthesis of α-, β-, and γ-AAs, as well as for the selective derivatisation of canonical and non-canonical α-AAs.
Topics: Amino Acids; Humans; Peptides; Photochemistry
PubMed: 32841470
DOI: 10.1002/anie.202010157 -
The Plant Cell Dec 2014The superfamily of phytochrome (Phy) photoreceptors regulates a wide array of light responses in plants and microorganisms through their unique ability to reversibly... (Review)
Review
The superfamily of phytochrome (Phy) photoreceptors regulates a wide array of light responses in plants and microorganisms through their unique ability to reversibly switch between stable dark-adapted and photoactivated end states. Whereas the downstream signaling cascades and biological consequences have been described, the initial events that underpin photochemistry of the coupled bilin chromophore and the ensuing conformational changes needed to propagate the light signal are only now being understood. Especially informative has been the rapidly expanding collection of 3D models developed by x-ray crystallographic, NMR, and single-particle electron microscopic methods from a remarkably diverse array of bacterial Phys. These structures have revealed how the modular architecture of these dimeric photoreceptors engages the buried chromophore through distinctive knot, hairpin, and helical spine features. When collectively viewed, these 3D structures reveal complex structural alterations whereby photoisomerization of the bilin drives nanometer-scale movements within the Phy dimer through bilin sliding, hairpin reconfiguration, and spine deformation that ultimately impinge upon the paired signal output domains. When integrated with the recently described structure of the photosensory module from Arabidopsis thaliana PhyB, new opportunities emerge for the rational redesign of plant Phys with novel photochemistries and signaling properties potentially beneficial to agriculture and their exploitation as optogenetic reagents.
Topics: Bacteria; Cyanobacteria; Models, Molecular; Nuclear Magnetic Resonance, Biomolecular; Phytochrome; Plants; Protein Structure, Tertiary; Signal Transduction
PubMed: 25480369
DOI: 10.1105/tpc.114.131623