Photo induced electron transfer photo induced photochemical processes. Medical search. Frequent questions

Photochemical reactions proceed differently than temperature-driven reactions. (wikipedia.org)
Photochemical paths access high energy intermediates that cannot be generated thermally, thereby overcoming large activation barriers in a short period of time, and allowing reactions otherwise inaccessible by thermal processes. (wikipedia.org)
Photochemical reactions require a light source that emits wavelengths corresponding to an electronic transition in the reactant. (wikipedia.org)
They were based on the effects of electron and nuclear spins in particular and on magnetic interaction in general, on the rates and yields of chemical and biological reactions. (europa.eu)
1. study of photochemical reactions involving proteins and protein related molecules. (europa.eu)
It is only by having a detailed understanding of all these factors that we can design chemical systems in which we have control over the direction and outcome of photochemical reactions. (durham.ac.uk)
This comprehensive approach is applied to the study of a number of photo-induced reactions, such as energy transfer, electron transfer and isomerisation. (durham.ac.uk)
B) The use of photochemical reagents to carry out site-specific reactions on DNA, in particular those involving photo-induced electron transfer. (tcd.ie)
Recently efforts have been directed towards understanding the very first events, i.e. energy transfer, that take place between the absorption of UV radiation and chemical reactions. (rsc.org)
Although photoinduced electron transfer reactions have been very intensively studied, several important questions still remain unanswered. (uzh.ch)
In the case of photochemical reactions, light provides the activation energy. (nationalvendingblog.com)
The entire capability of nanocrystals in semi-conductors and plasmons may now be investigated and photochemical reactions can concurrently be generated and observed. (techthoroughfare.com)
This effect can be used to modify reaction pathways of chemical and photo-chemical reactions. (su.se)
In Type I, light energy passes from excited molecules to biomolecules through electron/hydrogen transfer (radical mechanism) in direct-contact reactions [Figure 1] and culminates in specific damage to biomolecules and in the initiation of radical chain reactions. (oaepublish.com)
Successful time-resolved crystallography studies have used the pump-probe approach, and the light-induced X-ray crystallographic difference densities have been assigned to reactions and excited-state processes. (nature.com)
The work integrates studies of fundamental properties of iron-sulfur clusters and their function in electron transfer and chemical reactions (H2, O2 activation). (academicjobs.net)
The candidate's research responsibilities will encompass the application of optical spectroscopy, photochemistry, and electron paramagnetic resonance spectroscopy (EPR) towards the broader goal of understanding how reduction-oxidation reactions integrate with photosynthetic reaction centers and electron transfer. (academicjobs.net)
The primary responsibility will be to conduct basic research on photosynthetic reaction centers and enzymes that integrate with the light reactions using a variety of methods including protein expression and anaerobic protein purification, biochemical analysis, photochemical EPR, and photochemical reactions. (academicjobs.net)

We have investigated the fundamental photophysical properties of lanthanide ions, including an understanding of the pathways of energy transfer from organic chromophores to the metal ions. (durham.ac.uk)
Reported in this review are the photochemical and photophysical properties of a group of symmetric, multinuclear complexes of the general form [L′(CN) 4 M(CN)-(PtL 4 )-(NC)-M(CN) 4 L′] n- (where M is a Group 8 metal, L is an amine, and L′ is a σ-donor ligand) that provide for apparent photoinduced multielectron charge transfer. (princeton.edu)
Photochemical and photophysical processes in biomolecules are intimately involved in a multitude of functional processes, that include vision, photosynthesis, molecular recognition, gene replication, etc., and can be utilized in areas such as photodynamic therapy. (rsc.org)
Based on the detailed photochemical and photophysical characterization a molecular keypad lock and a D-latch memory device were developed and demonstrated. (uhu.es)

Photochemical and Photobiological Sciences (2012) 11 , 1151-1155. (nyu.edu)

The reactivity of these complexes as a function of Group 8 metal and solvent system is nicely predicted using the charge transfer theories of Marcus and Hush, with the source of the differential reactivity being the shift in the relative activation barriers for the conversion of a one-electron [Fe III , Pt III , Fe II ] intermediate to the observed two-electron products or to the starting material. (princeton.edu)
The photochemical reactivity and photophysics of these species are found to be a function of molecular geometry. (princeton.edu)

The first law of photochemistry, known as the Grotthuss-Draper law (for chemists Theodor Grotthuss and John W. Draper), states that light must be absorbed by a chemical substance in order for a photochemical reaction to take place. (wikipedia.org)
According to the second law of photochemistry, known as the Stark-Einstein law (for physicists Johannes Stark and Albert Einstein), for each photon of light absorbed by a chemical system, no more than one molecule is activated for a photochemical reaction, as defined by the quantum yield. (wikipedia.org)
The observed reaction is found to selectively yield two-electron products. (princeton.edu)
The presence of the bicontinuous structures formed by the upconverting fibrous nanoassemblies and the solution phase is utilized to design photochemical reaction systems induced by TTA-UC. (mdpi.com)
The structural dynamics that result from femtosecond optical excitation have contributions from vibrational and electronic processes and from reaction dynamics that involve the crossing through a conical intersection. (nature.com)
However, we demonstrate that the measured motions are not part of the photoisomerization reaction but instead arise from impulsively driven coherent vibrational processes in the electronic ground state. (nature.com)

Devices based upon organic materials rely upon the recombination of holes and electrons that are injected into the material producing excited states, known as excitons, which can be either triplet or singlet character. (durham.ac.uk)

They possess easily accessible close-lying electronic states that lead to a plethora of complex and ultrafast photochemical processes during the first steps of energy conversion. (nature.com)
The group works on a wide variety of topics involving photo chemistry, coherent control, polaritonic chemistry, ultrafast spectroscopy, and numerical methods related to quantum dynamics. (su.se)
His research interests are in the application of ultrafast X ray spectroscopy and scattering techniques to investigate atomic and electronic structural dynamics in condensed matter including transition-metal complexes, molecular dynamics in solution, and electronic phase transitions in correlated electron systems. (stanford.edu)

Major current research topics are (i) the characterization of supramolecular assemblies , (ii) the study of photochemical processes and, more recently, (iii) the characterization of electrochemical processes . (ulb.be)
X = Cl, Br, I). Electrochemical and photochemical properties and behavior. (univ-grenoble-alpes.fr)
Her research interests include the advanced materials processing of ideal electrode materials for electrochemical energy storage system applications such as supercapacitor, water splitting process, direct methanol fuel cells, and hydrogen generation. (rsc.org)
The direct photo-electrochemical conversion of water and CO 2 into chemical fuels represents an exciting new pathway for the combined conversion and storage of solar energy. (uzh.ch)
Electrochemical elaboration of thin films of poly[RuII(L)(CO)2Cl2] (L = 4-(2-pyrrol-1-ylethyl)-4'-methyl-2,2'-bipyridine or 4,4'-bis((3-pyrrol-1-ylpropyloxy)carbonyl)-2,2'-bipyridine): photochemical properties and photoimaging. (univ-grenoble-alpes.fr)

Further investigate reveals that the nanotwins inside the Cu 7 S 4 microcages can facilite the transport of free charges, decrease the recombination of photoinduced electrons and holes, and elongate the lifetime of the electron-hole pairs. (frontiersin.org)

Photoexcitation is the first step in a photochemical process where the reactant is elevated to a state of higher energy, an excited state. (wikipedia.org)
The photon can be absorbed directly by the reactant or by a photosensitizer, which absorbs the photon and transfers the energy to the reactant. (nationalvendingblog.com)

A major achievement is the development of Photo-Chemically Induced Dynamic Nuclear Polarization (photo-CIDNP) measurements for the characterization of photo-induced electron transfer processes with metal complexes. (ulb.be)
This doctoral thesis contributes to these activities with the design and characterization of new molecular switches and model systems that can be used to study energy transfer processes. (uhu.es)

2. investigation of structure, i.e. surface accessibility and confinement, and dynamic processes, i.e. intermolecular electron and proton transfer, in native and ill defined partly folded and denatured states of proteins as promising new applications. (europa.eu)
They found out that an important radiationless pathway for the AMOX-(H 2 O) 5 cluster involves an electron-driven proton transfer along water wires. (compchemhighlights.org)
Fig. 1 - Electron-driven proton transfer along water wires. (compchemhighlights.org)

Although true multielectron charge transfer processes do not exist within the realm of molecular photochemistry, one can design mimicking systems via the production of a reactive one-electron charge transfer intermediate. (princeton.edu)
However, multielectron charge transfer photochemistry can be observed for M = Os or Ru only by using a mixed DMSO-aqueous solvent, in which the cyanide to water hydrogen bonding found in pure aqueous solvent is destroyed, thereby, shifting the redox potential of the cyanometalates to values similar to M = Fe. (princeton.edu)

Photoinduced energy and electron transfer processes in heteropolynuclear polypyridyl complexes of Ru(II) and Fe(II). (univ-grenoble-alpes.fr)

Hydrocarbon solvents absorb only at short wavelengths and are thus preferred for photochemical experiments requiring high energy photons. (wikipedia.org)
Cellulose acetate is photo chemically degraded by UV wavelengths shorter than 280 nm, but has limited photo degradability in sunlight due to the lack of chromophores for absorbing ultraviolet light. (springer.com)

In sharp contrast, however, information on electronic processes in biomolecules such as isolated proteins and DNA (and their complexes) is still in its infancy. (rsc.org)
Though extremely complicated to uncover, knowledge of photo-excited state processes of such biomolecules in the cellular/biological context is the eventual goal of scientists working in these areas. (rsc.org)

Light induced chemical and physical processes in small organic-/inorganic-/bio-molecules have been a subject of experimental and theoretical research for several decades. (rsc.org)
Recent advances in high resolution spatio-temporal techniques have offered detailed understanding of excited state processes in small molecules. (rsc.org)
They were able to view the production of radical species - molecules with an unpaired electron - as well as the results of their assembly, such as sigma dimeric viologen species, which are formed when two radicals establish a reversible carbon-carbon bond. (techthoroughfare.com)
With the advancement of cavity quantum electrodynamics and its recent application to molecules, using the quantum properties of light to control photo-chemistry has come into reach. (su.se)
This process occurs in an electronic state characterized by an electron transfer from an n orbital at the chromophore to a σ* orbital in one of the water molecules (Fig. 1). (compchemhighlights.org)

The work involved the application of the nuclear magnetic resonance (NMR) technique termed Chemically induced dynamic nuclear polarisation (CIDNP) that allowed for high sensitivity and spectral resolution in crowded spectra combined with optical initiation of chemical intermediates. (europa.eu)

Balzani, V. Photochemical molecular devices. (nature.com)
As an additional advantage the logic functions can be reset and reconfigured, which makes the system a versatile platform for molecular information processing. (uhu.es)
Such switches are not trivial and the developed research is without doubt at the frontline of these recent developments in molecular information processing. (uhu.es)
There is a constant interest of using energy transfer as design principle for molecular dyads with the most diverse functions. (uhu.es)
Towards New Molecular Photocatalysts for CO2 Reduction: Photo-Induced Electron Transfer versus CO Dissociation within [Os(NN)(CO)2Cl2] Complexes. (univ-grenoble-alpes.fr)
In self-limiting processes, nature regulates the assembling of complex structures on the molecular scale. (techthoroughfare.com)

Addressing those 'big questions' of high societal relevance have the merit of creating high visibility and also funding opportunities, however, classic comparative physiology and biochemistry is running the risk of becoming marginalized in this process, if the underlying physiological and biochemical processes cannot be visualized accordingly. (easychair.org)

An host-guest complex between the cucurbit[7]uril organic macrocycle and a pH-dependent fluorescent naphthalimide-benzimidazole guest were used to demonstrate the macrocycle-induced control of photoinduced electron transfer of the guest. (uhu.es)
Next, I will present charge transfer dynamics from methyl ammonium lead iodide perovskites to organic hole transporting materials. (uzh.ch)
Most emitted air pollution can lead to the formation of secondary pollutants (e.g., tropospheric ozone, peroxyacetyl nitrate), secondary organic aerosols, and photochemical smog [ 6 , 7 ], which is the major cause of a sharp decrease in air quality in numerous regions around the world [ 8 - 10 ]. (nso-journal.org)

In addition, this session will also deal with the photo-repair of nucleic acids and proteins. (rsc.org)

Photoinduced charge transfer processes have been implicated in a variety of oxidative processes which ultimately lead to mutations, compromising the biological function of DNA. (rsc.org)
Interpretation of the mechanism and dynamics of photoexcited state processes is of paramount importance to understanding DNA oxidative damage. (rsc.org)

The camera collects lights in semiconductors, causing processes of electron transfer, such as photosynthesis, which can be examined using spectroscopic methods and gold nanoparticles. (techthoroughfare.com)

Our work is currently focussing on the synthesis and characterisation of luminescent dimeric phthalocyanines with interesting properties, the protonation of phthalocyanines and the preparation of electron-donor phthalocyanine dyads. (durham.ac.uk)
Herein several aminonaphthalimide-fullerene dyads were investigated and quantitative energy transfer was shown. (uhu.es)
The other type of energy transfer dyads used again an aminonaphthalimide as energy donor and a BODIPY dye as acceptor. (uhu.es)
In this thesis it was shown that highly efficient energy transfer can be observed in the investigated aminonaphthalimide-BODIPY dyads. (uhu.es)
Electron Transfer Across Modular Oligo-p-phenylene Bridges in Ru(bpy)2(bpy-phn-DQ)4+ (n = 1-5) Dyads. (univ-grenoble-alpes.fr)

The oxidation channel via electron transfer from the amino group was revealed. (europa.eu)
Titanium dioxide is commonly added to enhance the whiteness of CA materials, and is a photo oxidation catalyst that causes degradation in sunlight. (springer.com)

We have identified the hydrogenation of the bridging ligand, which inhibits the light-driven electron transfer between the photocentre and catalytic centre, as the deactivation mechanism. (nature.com)
The camera is utilized to monitor catalytic photography and monitor light-induced electron transfer. (techthoroughfare.com)

When a molecule or atom in the ground state (S0) absorbs light, one electron is excited to a higher orbital level. (wikipedia.org)

The mechanism and dynamics of photoinduced DNA and protein damage is critically important to our understanding of diseases associated with ultraviolet irradiation as well as to the development of photosensitized therapies. (rsc.org)
Ultra short laser pulses in the extreme ultraviolet and X-ray laser regime, as they are provided by free electron laser and high harmonic generation sources, fulfill the spectral and temporal requirements to resolve the coupled nuclear+electronic dynamics in the vicinity of CoIns. (su.se)

This session will discuss recent progress in the photoinduced processes related to proteins that are responsible for vision that include i) rhodopsin in the photoreceptor cells of the vertebrate ii) retina, phytochrome in plants, and bacteriorhodopsin and bacteriophytochromes in some bacteria. (rsc.org)
This session will highlight the consequences of photoinduced processes in DNA or proteins responsible for the onset of various types of disease (particularly melanoma cancer). (rsc.org)

In order to increase the inherently small Stokes shift of the BODIPY dye an antenna chromophore can be used that transfers its excitation energy to the acceptor dye. (uhu.es)
As a special twist the energy transfer works not only under conditions of one-photon excitation but also in the non-linear two-photon absorption regime. (uhu.es)
A 10fs X-ray pump pulse creates a localized excitation by removing a 1s electron from an Fe atom in solvated ferro- and ferricyanide complexes. (stanford.edu)
A coherent-control experiment using a two-colour and two-pulse optical excitation strongly amplifies the X-ray crystallographic difference density, while it fully depletes the photoisomerization process. (nature.com)

Recent, ground breaking experiments have show that one can utilize the vacuum field of an optical nano-resonator to significantly modify the potential energy landscape and thus its photo-chemistry. (su.se)

In the case where M = Fe, irradiation into the IVCT band centered at 425 nm produces a net two-electron charge transfer with a quantum yield of ca. 0.1 in an aqueous solvent. (princeton.edu)
From the photochemical point of view, the solvent was understood as an important but passive factor. (compchemhighlights.org)

The mechanism of CO release involves periodic transitions between the initially excited metal-to-ligand charge-transfer state and dissocative metal--centered states. (nature.com)
Therefore, exploring the related process mechanism is of significant importance. (frontiersin.org)
Photo degradation is another common mechanism for many polymers. (springer.com)

Photoinduced inter-protein electron transfer is also responsible for various biological processes. (rsc.org)

Oxygen atom functionalization has played an indispensable role in industrial applications and biological processes. (rsc.org)

In general, excited species are prone to participate in electron transfer processes. (wikipedia.org)

But at the same time, they have an electron in a high energy orbital, and are thus more reducing. (wikipedia.org)

Chan, M. S. and J. R. Bolton (1980) Structures, reduction potentials and absorption maxima of synthetic dyes of interest in photochemical solar-energy storage studies. (photochemcad.com)

3. modelling of non-enzymatic Deoxyribonucleic acid (DNA) repair via electron transfer from amino acids to the oxidised purine nucleotides that we recently found as a prototype of fast chemical repair of radiation induced damages of DNA and extending the findings to systems with increased complexity within the frame of proteomic research on peculiarities of recognition and processing of DNA substrate. (europa.eu)
These processes are studied in a range of chemical systems including commercially important materials, e.g. pharmaceuticals & electroluminescent materials, compounds of fundamental interest, e.g. those that show twisted intramolecular charge transfer (TICT) states, and new materials such as C 60 and electroluminescent materials. (durham.ac.uk)
In the few steps of the process, there are very few equipments used like the chemical reagent, maskants, and etchants. (nationalvendingblog.com)
The benefits of chemical etching should be considered in the Design For Manufacturing process when choosing a manufacturing method for industrial components. (nationalvendingblog.com)
The elimination of mechanical tooling and its long lead time, the absence of surface burrs and deburring requirements, plus the speed with intricate designs makes photo chemical etching a fast manufacturing process for prototypes or large production. (nationalvendingblog.com)
With the new insight and tools we want to propose new photo-chemical applications. (su.se)
Various studies have been conducted on the biodegradability of cellulose acetate, but no review has been compiled which includes biological, chemical, and photo chemical degradation mechanisms. (springer.com)

Studies of Phthalocyanines Our group carries out fundamental research into the photochemical properties of phthalocyanines, a class of compound that that has a wide range of applications including photodynamic therapy, PDT. (durham.ac.uk)

Some of the mentioned photochromic switches rely on energy transfer as excited state process. (uhu.es)
When a semiconductor photocatalyst initiates by an appropriate light source with energy greater than its bandgap energy, the electrons (e − ) can transfer from the valence band (VB) to its conduction band (CB), and then leave holes (h + ) in the corresponding position of the VB. (nso-journal.org)

I have myself contributed to the field by showing a case where a water-to-chromophore electron transfer could create a conical intersection (3). (compchemhighlights.org)
3) Barbatti, M. Photorelaxation Induced by Water-Chromophore Electron Transfer. (compchemhighlights.org)

Such processes in DNA are also of interest to both the biological and materials communities as memory devices and structural building blocks. (rsc.org)

Malign consequences of mis-function in higher life forms can include blindness (retinal pigmentosa), as well as photomutation leading, in DNA, to the primary cause of various types of cancer which (when light induced) can lead to melanomas. (rsc.org)
Most photochemical transformations occur through a series of simple steps known as primary photochemical processes. (nationalvendingblog.com)

In their study they resolve the initial events and find that a bright metal-to-ligand charge-transfer transition induces synchronous Fe-CO oscillations, followed by sequential transitions to dissociative metal-centered excited states. (nature.com)
Metastasis are characterized by a sequential and complex process during which cancer cells invade specific organs including lung, liver, brain, and bone [ 3 ] . (oaepublish.com)

this process is called fluorescence. (wikipedia.org)
This process implies a change of electronic spin, which is forbidden by spin selection rules, making phosphorescence (from T1 to S0) much slower than fluorescence (from S1 to S0). (wikipedia.org)

Careful comparison of the experimental spectra with theory, extracts +2eV shifts in transition energies per valence hole, providing insight into correlated interactions of valence 3d with 3p and deeper-lying electrons. (stanford.edu)

These complexes exhibit intense intervalence charge transfer (IVCT) bands in the blue portion of the optical spectrum (350-450 nm). (princeton.edu)
Photoexcitation of the ironpentacarbonyl complex from the electronic ground state (GS) into a metal-to-ligand charge-transfer (MLCT) state triggers Fe-CO oscillations, which after electronic rearrangement into a metal-centered state (MC) lead to periodic bursts of carbonmonooxide (CO). (nature.com)

The photodissociation of transition metal carbonyls is involved in catalysis and synthetic processes. (nature.com)

Candidates with additional experience or knowledge of the use of photo-driven methods in the study of enzymes will be strongly considered. (academicjobs.net)

ii) response to light and ii) electron transfer processes in a variety of organisms are subjects of great importance. (rsc.org)

Domcke, W. Computational investigation of the photoinduced homolytic dissociation of water in the pyridine-water complex. (compchemhighlights.org)

Photo etched parts eliminate the need for the costly secondary deburring operation that may be necessary for other manufacturing processes. (nationalvendingblog.com)
Here are the advantages of photo etching compared to other manufacturing processes: Photo etching tooling is digital, unlike costly conventional methods such as stamping. (nationalvendingblog.com)
However, it is frequently time-consuming, costly, and sophisticated methods to imitate these processes in the laboratory. (techthoroughfare.com)
In addition, the replacement, cleaning, and disposal of adsorbent materials are costly processes and may cause secondary pollution. (nso-journal.org)

According to him, this system will open up a large variety of processes, including numerous materials and chemistries that are critical for developing sustainable technology. (techthoroughfare.com)

We covered topics going from the photochemical mechanisms involved, the different cell death mechanisms being triggered by a myriad of photosensitizers up to the more recent-on-going clinical trials. (oaepublish.com)

Anatomy6

Organisms25

Diseases1

Chemicals and Drugs126

Analytical, Diagnostic and Therapeutic Techniques and Equipment38

Psychiatry and Psychology1

Phenomena and Processes49

Disciplines and Occupations6

Technology, Industry, Agriculture3

Information Science4

Health Care5

Reactions18

Photophysical4

Photobiological Sciences1

Reactivity2

Reaction6

Holes and electrons1

Ultrafast3

Electrochemical5

Recombination1

Reactant2

Characterization2

Proton transfer3

Photochemistry2

Polypyridyl1

Wavelengths2

Biomolecules2

Molecules5

Intermediates1

Molecular6

Biochemical1

Organic3

Nucleic acids1

Oxidative2

Photosynthesis1

Dyads5

Oxidation2

Catalytic2

Absorbs1

Dynamics2

Proteins2

Excitation4

Experiments1

Solvent2

Mechanism3

Protein1

Atom1

Species1

Orbital1

Absorption1

Chemical7

Properties1

Energy2

Chromophore2

Biological1

Primary2

Sequential2

Fluorescence2

Valence1

Charge transfer2

Synthetic1

Study1

Light1

Complex1

Costly4

System1

Mechanisms1