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Phenanthrene is used to make dyes, plastics, pesticides, explosives, and drugs. It has also been used to make bile acids, cholesterol and steroids. [3] Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke, but there are many routes of exposure.
Water vapor concentration for this gas mixture is 0.4%. Water vapor is a greenhouse gas in the Earth's atmosphere, responsible for 70% of the known absorption of incoming sunlight, particularly in the infrared region, and about 60% of the atmospheric absorption of thermal radiation by the Earth known as the greenhouse effect. [25]
It has been prepared by oxidation of phenanthrene with chromic acid. [3] It is used as an artificial mediator for electron acceptor/donor in Mo/W containing formate dehydrogenase reduction of carbon dioxide to formate and vice versa. It is a better electron acceptor than the natural nicotinamide adenine dinucleotide (NAD +).
In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound. It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [ 1 ]
Förster resonance energy transfer (FRET or FET) is a dynamic quenching mechanism because energy transfer occurs while the donor is in the excited state. FRET is based on classical dipole-dipole interactions between the transition dipoles of the donor and acceptor and is extremely dependent on the donor-acceptor distance, R , falling off at a ...
The analogous cyclic system appears to have even more resonance stabilized, as the negative charge can be delocalized across three carbons instead of two. However, the cyclopropenyl anion has 4 π electrons in a cyclic system and in fact has a substantially higher p K a than 1-propene because it is antiaromatic and thus destabilized. [ 3 ]
Thus, the lifetime of a particle is the direct inverse of the particle's resonance width. For example, the charged pion has the second-longest lifetime of any meson, at 2.6033 × 10 −8 s. [2] Therefore, its resonance width is very small, about 2.528 × 10 −8 eV or about 6.11 MHz. Pions are generally not considered as "resonances".
The shape of lines in a nuclear magnetic resonance (NMR) spectrum is determined by the process of free induction decay. This decay is approximately exponential, so the line shape is Lorentzian. [11] This follows because the Fourier transform of an exponential function in the time domain is a Lorentzian in the frequency domain.