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Photochemistry and Photobiology Nov 2021The enclosed is a special retirement issue of Photochemistry and Photobiology, dedicated to Edward L. Clennan. Papers are included by those with ties to Ed as former...
The enclosed is a special retirement issue of Photochemistry and Photobiology, dedicated to Edward L. Clennan. Papers are included by those with ties to Ed as former group members, collaborators, and colleagues. They cover a range of topics in photochemistry, photosensitization, photocatalysis, chemiluminescence, photorelease, helical compounds, and reactive intermediates, all of which are very fitting to Ed's contributions in fundamental science. His efforts include essential contributions to mechanisms of singlet oxygen in homogeneous and heterogeneous media, as well as photoinduced electron transfer reactions and photocyclizations to form helicenes. The latter topics also have potential use in organic electronic devices.
Topics: Humans; Photobiology; Photochemistry; Photosensitivity Disorders; Retirement; Singlet Oxygen
PubMed: 34918355
DOI: 10.1111/php.13497 -
Chemistry (Weinheim An Der Bergstrasse,... Nov 2021Melanin-like nanomaterials have found application in a large variety of high economic and social impact fields as medicine, energy conversion and storage, photothermal... (Review)
Review
Melanin-like nanomaterials have found application in a large variety of high economic and social impact fields as medicine, energy conversion and storage, photothermal catalysis and environmental remediation. These materials have been used mostly for their optical and electronic properties, but also for their high biocompatibility and simplicity and versatility of preparation. Beside this, their chemistry is complex and it yields structures with different molecular weight and composition ranging from oligomers, to polymers as well as nanoparticles (NP). The comprehension of the correlation of the different compositions and morphologies to the optical properties of melanin is still incomplete and challenging, even if it is fundamental also from a technological point of view. In this minireview we focus on scientific papers, mostly recent ones, that indeed examine the link between composition and structural feature and photophysical and photochemical properties proposing this approach as a general one for future research.
Topics: Melanins; Nanoparticles; Nanostructures; Photochemistry; Polymers
PubMed: 34505731
DOI: 10.1002/chem.202102479 -
Methods in Molecular Biology (Clifton,... 2018Providing sufficient amount of oxygen to the cells is a critical issue since the lack of adequate oxygen leads to cell death and tissue necrosis. Therefore, there is a...
Providing sufficient amount of oxygen to the cells is a critical issue since the lack of adequate oxygen leads to cell death and tissue necrosis. Therefore, there is a vital need to design and fabricate oxygen-generating biomaterials to mitigate hypoxia-induced cell death in engineered tissues. Here, we report the fabrication of an oxygen-generating hydrogel by incorporating calcium peroxide (CPO) into the methacrylated gelatin (GelMA) structure using photocrosslinking process. A sustainable release of oxygen could be provided from CPO-GelMA hydrogel over a period of 5 days under hypoxic conditions (1% O).
Topics: Cross-Linking Reagents; Hydrogel, Polyethylene Glycol Dimethacrylate; Oxygen; Photochemistry
PubMed: 29633218
DOI: 10.1007/978-1-4939-7792-5_19 -
Journal of the American Chemical Society Sep 2022The odyssey of photochemistry is accompanied by the journey to manipulate "electrons" and "protons" in time, in space, and in energy. Over the past decades,... (Review)
Review
The odyssey of photochemistry is accompanied by the journey to manipulate "electrons" and "protons" in time, in space, and in energy. Over the past decades, single-electron (1e) photochemical transformations have brought marvelous achievements. However, as each photon absorption typically generates only one exciton pair, it is exponentially challenging to accomplish multielectron and proton photochemical transformations. The multistep differences in thermodynamics and kinetics urgently require us to optimize light harvesting, expedite consecutive electron transfer, manipulate the interaction of catalysts with substrates, and coordinate proton transfer kinetics to furnish selective bond formations. Tandem catalysis enables orchestrating different photochemical events and catalytic transformations from subpicoseconds to seconds, which facilitates multielectron redox chemistries and brings consecutive, value-added reactivities. Joint efforts in molecular and material design, mechanistic understanding, and theoretical modeling will bring multielectron and proton synthetic opportunities for fuels, fertilizers, and chemicals with enhanced versatility, efficiency, selectivity, and scalability, thus taking better advantage of photons (i.e., sunlight) for our sustainable society.
Topics: Electron Transport; Electrons; Oxidation-Reduction; Photochemistry; Protons
PubMed: 36054091
DOI: 10.1021/jacs.2c02341 -
Physical Chemistry Chemical Physics :... Oct 2020In this perspective review article, we have attempted to bring out the important current trends of research in the areas of supramolecular and suprabiomolecular... (Review)
Review
In this perspective review article, we have attempted to bring out the important current trends of research in the areas of supramolecular and suprabiomolecular photochemistry. Since the spans of the subject areas are very vast, it is impossible to cover all the aspects within the limited space of this review article. Nevertheless, efforts have been made to assimilate the basic understanding of how supramolecular interactions can significantly change the photophysical and other related physiochemical properties of chromophoric dyes and drugs, which have enormous academic and practical implications. We have discussed with reference to relevant chemical systems where supramolecularly assisted modulations in the properties of chromophoric dyes and drugs can be used or have already been used in different areas like sensing, dye/drug stabilization, drug delivery, functional materials, and aqueous dye laser systems. In supramolecular assemblies, along with their conventional photophysical properties, the acid-base properties of prototropic dyes, as well as the excited state prototautomerization and related proton transfer behavior of proton donor/acceptor dye molecules, are also largely modulated due to supramolecular interactions, which are often reflected very explicitly through changes in their absorption and fluorescence characteristics, providing us many useful insights into these chemical systems and bringing out intriguing applications of such changes in different applied areas. Another interesting research area in supramolecular photochemistry is the excitation energy transfer from the donor to acceptor moieties in self-assembled systems which have immense importance in light harvesting applications, mimicking natural photosynthetic systems. In this review article, we have discussed varieties of these aspects, highlighting their academic and applied implications. We have tried to emphasize the progress made so far and thus to bring out future research perspectives in the subject areas concerned, which are anticipated to find many useful applications in areas like sensors, catalysis, electronic devices, pharmaceuticals, drug formulations, nanomedicine, light harvesting, and smart materials.
Topics: Energy Transfer; Fluorescent Dyes; Light; Photochemistry
PubMed: 33112299
DOI: 10.1039/d0cp03981k -
Molecules (Basel, Switzerland) Jan 2021The covalent and noncovalent association of self-assembling peptides and tetrapyrroles was explored as a way to generate systems that mimic Nature's functional... (Review)
Review
The covalent and noncovalent association of self-assembling peptides and tetrapyrroles was explored as a way to generate systems that mimic Nature's functional supramolecular structures. Different types of peptides spontaneously assemble with porphyrins, phthalocyanines, or corroles to give long-range ordered architectures, whose structure is determined by the features of both components. The regular morphology and ordered molecular arrangement of these systems enhance the photochemical properties of embedded chromophores, allowing applications as photo-catalysts, antennas for dye-sensitized solar cells, biosensors, and agents for light-triggered therapies. Chemical modifications of peptide and tetrapyrrole structures and control over the assembly process can steer the organization and influence the properties of the resulting system. Here we provide a review of the field, focusing on the assemblies obtained from different classes of self-assembling peptides with tetrapyrroles, their morphologies and their applications as innovative functional materials.
Topics: Indoles; Isoindoles; Peptides; Photochemistry; Porphyrins; Tetrapyrroles
PubMed: 33525730
DOI: 10.3390/molecules26030693 -
Environmental Science. Processes &... Jan 2020Light energy is a driver for many biogeochemical element cycles in aquatic systems. The sunlight-induced photochemical reduction of ferric iron (Fe(iii) photoreduction)... (Review)
Review
Light energy is a driver for many biogeochemical element cycles in aquatic systems. The sunlight-induced photochemical reduction of ferric iron (Fe(iii) photoreduction) to ferrous iron (Fe(ii)) by either direct ligand-to-metal charge transfer or by photochemically produced radicals can be an important source of dissolved Fe in aqueous and sedimentary environments. Reactive oxygen species (ROS) are formed by a variety of light-dependent reactions. Those ROS can oxidize Fe(ii) or reduce Fe(iii), and due to their high reactivity they are key oxidants in aquatic systems where they influence many other biogeochemical cycles. In oxic waters with circumneutral pH, the produced Fe(ii) reaches nanomolar concentrations and serves as a nutrient, whereas in acidic waters, freshwater and marine sediments, which are rich in Fe(ii), the photochemically formed Fe(ii) can reach concentrations of up to 100 micromolar and be used as additional electron donor for acidophilic aerobic, microaerophilic, phototrophic and, if nitrate is present, for nitrate-reducing Fe(ii)-oxidizing bacteria. Therefore, Fe(iii) photoreduction may not only control the primary productivity in the oceans but has a tremendous impact on Fe cycling in the littoral zone of freshwater and marine environments. In this review, we summarize photochemical reactions involving Fe, discuss the role of ROS in Fe cycling, and highlight the importance of photoreductive processes in the environment.
Topics: Bacteria; Ferric Compounds; Ferrous Compounds; Fresh Water; Iron; Nitrates; Oxidation-Reduction; Photochemistry
PubMed: 31904051
DOI: 10.1039/c9em00415g -
The Yale Journal of Biology and Medicine Dec 2017Nature has invented photoreceptor proteins that are involved in sensing and response to light in living organisms. Genetic code expansion (GCE) technology has provided... (Review)
Review
Nature has invented photoreceptor proteins that are involved in sensing and response to light in living organisms. Genetic code expansion (GCE) technology has provided new tools to transform light insensitive proteins into novel photoreceptor proteins. It is achieved by the site-specific incorporation of unnatural amino acids (Uaas) that carry light sensitive moieties serving as "pigments" that react to light via photo-decaging, cross-linking, or isomerization. Over the last two decades, various proteins including ion channels, GPCRs, transporters, and kinases have been successfully rendered light responsive owing to the functionalities of Uaas. Very recently, Cas9 protein has been engineered to enable light activation of genomic editing by CRISPR. Those novel proteins have not only led to discoveries of dynamic protein conformational changes with implications in diseases, but also facilitated the screening of ligand-protein and protein-protein interactions of pharmacological significance. This review covers the genetic editing principles for genetic code expansion and design concepts that guide the engineering of light-sensitive proteins. The applications have brought up a new concept of "optoproteomics" that, in contrast to "optogenetics," aims to combine optical methods and site-specific proteomics for investigating and intervening in biological functions.
Topics: Amino Acids; Animals; Gene Editing; Genetic Code; Humans; Mutagenesis, Site-Directed; Optogenetics; Photochemistry; Protein Engineering; Proteomics; RNA, Transfer; Recombinant Proteins
PubMed: 29259524
DOI: No ID Found -
Journal of Inorganic Biochemistry Jan 2023Iron is the trace element of natural selection by the biological systems due to its versatile coordination chemistry, and is recently explored for medicinal and... (Review)
Review
Iron is the trace element of natural selection by the biological systems due to its versatile coordination chemistry, and is recently explored for medicinal and diagnostic applications. Photo-activated states of iron complexes exhibiting substitution, dissociation, isomerization reactions, intramolecular redox reactions or energy transfer to other molecules have attracted the attention across the globe for the potent applications in photo-chemotherapy. There is a significant advancement on the development of iron-based complexes for photochemotherapeutic applications. Here in we reviewed the photo-activated states and photochemistry of iron complexes, and recent advances made in the area of photochemotherapy of iron complexes relevant to the photochemistry of iron complexes.
Topics: Iron; Photochemotherapy; Photochemistry; Oxidation-Reduction; Coordination Complexes
PubMed: 36335746
DOI: 10.1016/j.jinorgbio.2022.112055 -
Journal of Environmental Sciences... Oct 2017
Topics: Catalysis; Environmental Pollutants; Photochemical Processes; Photochemistry
PubMed: 29031438
DOI: 10.1016/j.jes.2017.09.012