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Tris(bipyridine)ruthenium(II) chloride is the chloride salt coordination complex with the formula [Ru(bpy) 3]Cl 2.This polypyridine complex is a red crystalline salt obtained as the hexahydrate, although all of the properties of interest are in the cation [Ru(bpy) 3] 2+, which has received much attention because of its distinctive optical properties.
In the "tris(bipy) complexes" three bipyridine molecules coordinate to a metal ion, written as [M(bipy) 3] n+ (M = metal ion; Cr, Fe, Co, Ru, Rh and so on). These complexes have six-coordinated, octahedral structures and exists as enantiomeric pairs: These and other homoleptic tris-2,2′-bipy complexes of many transition metals are
For the common photosensitizer, tris-(2,2’-bipyridyl)ruthenium (abbreviated as [Ru(bipy) 3] 2+ or [Ru(bpy) 3] 2+), the lifetime of the triplet excited state is approximately 1100 ns. This lifetime is sufficient for other relaxation pathways (specifically, electron-transfer pathways) to occur before decay of the catalyst to its ground state.
For example, electron donation, electron withdrawal, and π-conjugating groups, to the polypyridine moiety. The MLCT absorption band can be shifted, the emission wavelength can be changed, and the emission lifetime can be extended. [2] Tris(bipyridine)ruthenium(II) is the preeminent example of a polypyridine complex.
The one-electron universe postulate, proposed by theoretical physicist John Wheeler in a telephone call to Richard Feynman in the spring of 1940, is the hypothesis that all electrons and positrons are actually manifestations of a single entity moving backwards and forwards in time. According to Feynman:
Comparison of the evolution of the universe under Alfvén–Klein cosmology and the Big Bang theory. [1]Plasma cosmology is a non-standard cosmology whose central postulate is that the dynamics of ionized gases and plasmas play important, if not dominant, roles in the physics of the universe at interstellar and intergalactic scales.
Therefore, a theory is needed that integrates relativity theory and quantum theory. [3] Such an approach is attempted for instance with loop quantum cosmology, loop quantum gravity, string theory and causal set theory. [4] In quantum cosmology, the universe is treated as a wave function instead of classical spacetime. [5]
The theory explains that the universe will expand until all matter decays and ultimately turns to light. Since nothing in the universe would have any time or distance scale associated with it, the universe becomes identical with the Big Bang, resulting in a type of Big Crunch that becomes the next Big Bang, thus perpetuating the next cycle. [21]