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[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula O − 2. [1] The systematic name of the anion is dioxide(1−).The reactive oxygen ion superoxide is particularly important as the product of the one-electron reduction of dioxygen O 2, which occurs widely in nature. [2]
Thus, the Lewis structure O=O with all electrons in pairs does not accurately represent the nature of the bonding in molecular oxygen. However, the alternative structure •O–O• is also inadequate, since it implies single bond character, while the experimentally determined bond length of 121 pm [6] is much shorter than the single bond in ...
Reactive oxygen species (ROS) may attack guanine at the dinucleotide site, forming 8-hydroxy-2'-deoxyguanosine (8-OHdG), and resulting in a 5mCp-8-OHdG dinucleotide site. The base excision repair enzyme OGG1 targets 8-OHdG and binds to the lesion without immediate excision.
There are several known allotropes of oxygen. The most familiar is molecular oxygen (O 2), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (O 3). Others are: Atomic oxygen (O 1), a free radical. Singlet oxygen (O * 2), one of two metastable states of ...
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Tetraoxygen was first predicted in 1924 by Gilbert N. Lewis, who proposed it as an explanation for the failure of liquid oxygen to obey Curie's law. [1] Though not entirely inaccurate, computer simulations indicate that although there are no stable O 4 molecules in liquid oxygen, O 2 molecules do tend to associate in pairs with antiparallel spins, forming transient O 4 units. [2]
Molecular orbital diagram of two singlet excited states as well as the triplet ground state of molecular dioxygen. From left to right, the diagrams are for: 1 Δ g singlet oxygen (first excited state), 1 Σ + g singlet oxygen (second excited state), and 3 Σ − g triplet oxygen (ground state). The lowest energy 1s molecular orbitals are ...