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argon-ion lasers at 458 and 488 nm [5] Lasers emitting wavelengths below 445 nm appear violet, but are nonetheless also called blue lasers. Violet light's 405 nm short wavelength, on the visible spectrum, causes fluorescence in some chemicals, like radiation in the ultraviolet ("black light") spectrum (wavelengths less than 400 nm).
Photochemical immersion well reactor (50 mL) with a mercury-vapor lamp.. Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm).
Endogenous porphyrins that are light-absorbing compounds located within certain bacteria produce photosensitized reactions in the presence of light in the blue region of the spectrum (400-500 nm), [128] showing better antimicrobial efficacy than other wavelengths in the visible spectrum (e.g. green and red, 500-700 nm) in the absence of an ...
The light-harvesting system of PSI uses multiple copies of the same transmembrane proteins used by PSII. The energy of absorbed light (in the form of delocalized, high-energy electrons) is funneled into the reaction center, where it excites special chlorophyll molecules (P700, with maximum light absorption at 700 nm) to a higher energy level.
Emission spectrum of an ultraviolet deuterium arc lamp showing characteristic hydrogen Balmer lines (sharp peaks at 486 nm and 656 nm labeled D β and D α from left to right respectively), continuum emission in the ~160-400 nm region and Fulcher band emission between around 560 to 640 nm.
The [4+4] Photocycloaddition is a cycloaddition reaction in which two unsaturated molecules connect via four atoms from each molecule (hence "4 + 4") to create an eight-membered ring. As a photochemical reaction , it is promoted by some form of light, as opposed to a thermal process.
The proposed reaction mechanisms involve the creation of a highly reactive carbon radical from carbon monoxide and carbon dioxide which then reacts with photogenerated protons to ultimately form methane. Efficiencies of TiO 2-based photocatalysts are low, although nanostructures such as carbon nanotubes [58] and metallic nanoparticles [59] help.
Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by absorption of light or photons. It is defined as the interaction of one or more photons with one target molecule that dissociates into two fragments. [1]