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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 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 -
Cannabis and Cannabinoid Research Dec 2022Photochemistry is a powerful synthetic tool resulting in the construction of unique substances. Remarkably, photochemistry has been relatively underexplored in the...
Photochemistry is a powerful synthetic tool resulting in the construction of unique substances. Remarkably, photochemistry has been relatively underexplored in the cannabinoid area and represents a valuable opportunity for further discovery.
Topics: Photochemistry
PubMed: 36251456
DOI: 10.1089/can.2022.0113 -
Biochimica Et Biophysica Acta May 2014Light induced isomerization of the retinal chromophore activates biological function in all retinal protein (RP) driving processes such as ion-pumping, vertebrate vision... (Review)
Review
Light induced isomerization of the retinal chromophore activates biological function in all retinal protein (RP) driving processes such as ion-pumping, vertebrate vision and phototaxis in organisms as primitive as archea, or as complex as mammals. This process and its consecutive reactions have been the focus of experimental and theoretical research for decades. The aim of this review is to demonstrate how the experimental and theoretical research efforts can now be combined to reach a more comprehensive understanding of the excited state process on the molecular level. Using the Anabaena Sensory Rhodopsin as an example we will show how contemporary time-resolved spectroscopy and recently implemented excited state QM/MM methods consistently describe photochemistry in retinal proteins. This article is part of a Special Issue entitled: Retinal Proteins - You can teach an old dog new tricks.
Topics: Anabaena; History, 20th Century; History, 21st Century; Isomerism; Light; Models, Molecular; Photochemistry; Quantum Theory; Retinaldehyde; Sensory Rhodopsins; Spectrum Analysis; Thermodynamics; Time Factors
PubMed: 24099700
DOI: 10.1016/j.bbabio.2013.09.014 -
Philosophical Transactions. Series A,... Jul 2013The use of density functional theory (DFT) and time-dependent DFT (TD-DFT) to study the photochemistry of metal complexes is becoming increasingly important among... (Review)
Review
The use of density functional theory (DFT) and time-dependent DFT (TD-DFT) to study the photochemistry of metal complexes is becoming increasingly important among chemists. Computational methods provide unique information on the electronic nature of excited states and their atomic structure, integrating spectroscopy observations on transient species and excited-state dynamics. In this contribution, we present an overview on photochemically active transition metal complexes investigated by DFT. In particular, we discuss a representative range of systems studied up to now, which include CO- and NO-releasing inorganic and organometallic complexes, haem and haem-like complexes dissociating small diatomic molecules, photoactive anti-cancer Pt and Ru complexes, Ru polypyridyls and diphosphino Pt derivatives.
Topics: Binding Sites; Computer Simulation; Light; Models, Chemical; Models, Molecular; Molecular Conformation; Photochemistry; Transition Elements
PubMed: 23776295
DOI: 10.1098/rsta.2012.0134 -
Chemical Record (New York, N.Y.) Jun 2014Due to the narrow width of tubing/reactors used, photochemistry performed in micro- and mesoflow systems is significantly more efficient than when performed in batch due...
Due to the narrow width of tubing/reactors used, photochemistry performed in micro- and mesoflow systems is significantly more efficient than when performed in batch due to the Beer-Lambert Law. Owing to the constant removal of product and facility of flow chemical scalability, the degree of degradation observed is generally decreased and the productivity of photochemical processes is increased. In this Personal Account, we describe a wide range of photochemical transformations we have examined using both visible and UV light, covering cyclizations, intermolecular couplings, radical polymerizations, as well as singlet oxygen oxygenations.
Topics: 2,2'-Dipyridyl; Alkenes; Artemisinins; Catalysis; Cyclization; Light; Organometallic Compounds; Oxidation-Reduction; Photochemistry; Polymerization; Polymers; Singlet Oxygen
PubMed: 24890908
DOI: 10.1002/tcr.201402035 -
Biotechnic & Histochemistry : Official... Apr 2004An overview of the basic principles of photochemistry is presented to facilitate discussion of fluorescence, quenching and quantum yields. These topics in turn provide... (Review)
Review
An overview of the basic principles of photochemistry is presented to facilitate discussion of fluorescence, quenching and quantum yields. These topics in turn provide the foundation for an account of fluorescence spectroscopy and its application to microscopy. A brief overview of light microscopy and the application of fluorescence microscopy is given. The influences of molecular features, such as aromatic character and substitution patterns, on color and fluorescence are described. The concept of color fading is considered with particular reference to its effect on microscopic preparations. A survey of representative fluorescent probes is provided, and their sensitivity, application, and limitations are described. The phototoxicity of fluorescent molecules is discussed using biomembranes and DNA as examples of targets of toxicity. Photodynamic therapy, a relatively new clinical application of phototoxicity, is described. Both anticancer and antimicrobial applications are noted, and an assessment is given of the current ideas on the ideal physicochemical properties of the sensitizing agents for such applications.
Topics: Animals; Biology; Biomarkers; Cell Physiological Phenomena; Fluorescent Dyes; Humans; Medicine; Microscopy, Fluorescence; Molecular Probe Techniques; Photochemistry
PubMed: 15513709
DOI: 10.1080/10520290412331292400 -
Chimia Oct 2021
Topics: Chemistry; Photochemical Processes; Photochemistry
PubMed: 34728020
DOI: 10.2533/chimia.2021.890 -
Ultrafast photochemistry produces superbright short-wave infrared dots for low-dose in vivo imaging.Nature Communications Jun 2020Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of...
Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (AgS superdots) derived from chemically synthesized AgS dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated AgS superdots enable deep-tissue in vivo imaging at low excitation intensities (<10 mW cm) and doses (<0.5 mg kg), emerging as unrivaled contrast agents for NIR-II preclinical bioimaging. These results establish an approach for developing superbright NIR-II contrast agents based on the synergy between chemical synthesis and ultrafast laser processing.
Topics: Fluorescent Dyes; Nanoparticles; Optical Imaging; Photochemistry; Quantum Dots
PubMed: 32523065
DOI: 10.1038/s41467-020-16333-2 -
Chemphyschem : a European Journal of... Feb 2011
Topics: Fluorescence Resonance Energy Transfer; History, 20th Century; Models, Molecular; Photochemistry
PubMed: 21344585
DOI: 10.1002/cphc.201100041