WordNet

a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earths crust (同)O, atomic number 8

PrepTutorEJDIC

『酸素』(化学記号はO)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/04/15 01:32:06」(JST)

wiki en

[Wiki en表示]

There are several known allotropes of oxygen. The most familiar is molecular oxygen (O₂), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (O₃). Others include:

Atomic oxygen (O₁, a free radical)
Singlet oxygen (O₂*), either of two metastable states of molecular oxygen
Tetraoxygen (O₄), another metastable form
Solid oxygen, existing in six variously colored phases, of which one is O
8 and another one metallic

Atomic oxygen

Atomic oxygen, denoted O(³P), O(3P) or O((3)P),^[1] is very reactive, as the single atoms of oxygen tend to quickly bond with nearby molecules; on Earth's surface it does not exist naturally for very long, though in outer space, the presence of plenty of ultraviolet radiation results in a low Earth orbit atmosphere in which 96% of the oxygen occurs in atomic form.^[1]^[2]

Dioxygen

The common allotrope of elemental oxygen on Earth, O
2, is generally known as oxygen, but may be called dioxygen or molecular oxygen to distinguish it from the element itself. Elemental oxygen is most commonly encountered in this form, as about 21% (by volume) of Earth's atmosphere. Dioxygen can occur in metastable states, called singlet oxygen; in contrast, the ground state is known as triplet oxygen.

O
2 has a bond length of 121 pm and a bond energy of 498 kJ/mol.^[3] It is a colourless gas with a boiling point of −183 °C (90 K; −297 °F).^[4] It can be condensed out of air by cooling with liquid nitrogen, which has a boiling point of −196 °C (77 K; −321 °F). Liquid oxygen is pale blue in colour, and is quite markedly paramagnetic—liquid oxygen contained in a flask suspended by a string is attracted to a magnet.

Singlet oxygen

Singlet oxygen is the common name used for the two metastable states of molecular oxygen (O₂) with higher energy than the ground state triplet oxygen. Because of the differences in their electron shells, singlet oxygen has different chemical properties than triplet oxygen, including absorbing and emitting light at different wavelengths. It can be generated in a photosensitized process by energy transfer from dye molecules such as rose bengal, methylene blue or porphyrins, or by chemical processes such as spontaneous decomposition of hydrogen trioxide in water or the reaction of hydrogen peroxide with hypochlorite.

Ozone

Triatomic oxygen (Ozone, O₃), is a very reactive allotrope of oxygen that is destructive to materials like rubber and fabrics and is also damaging to lung tissue.^[5] Traces of it can be detected as a sharp, chlorine-like smell,^[4] coming from electric motors, laser printers, and photocopiers. It was named "ozone" by Christian Friedrich Schönbein, in 1840, from the Greek word ὠζώ (ozo) for smell.^[6]

Ozone is thermodynamically unstable toward the more common dioxygen form, and is formed by reaction of O₂ with atomic oxygen produced by splitting of O₂ by UV radiation in the upper atmosphere.^[6] Ozone absorbs strongly in the ultraviolet and functions as a shield for the biosphere against the mutagenic and other damaging effects of solar UV radiation (see ozone layer).^[6] Ozone is formed near the Earth's surface by the photochemical disintegration of nitrogen dioxide from the exhaust of automobiles.^[7] Ground-level ozone is an air pollutant that is especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma.^[8] The immune system produces ozone as an antimicrobial (see below).^[9] Liquid and solid O₃ have a deeper blue color than ordinary oxygen and they are unstable and explosive.^[6]^[10]

Ozone is a pale blue gas condensable to a dark blue liquid. It is formed whenever air is subjected to an electrical discharge, and has the characteristic pungent odour of new-mown hay, or for those living in urban environments, of subways – the so-called 'electrical odour'.

Tetraoxygen

Tetraoxygen had been suspected to exist since the early 1900s, when it was known as oxozone, and was identified in 2001 by a team led by F. Cacace at the University of Rome. The molecule O
4 was thought to be in one of the phases of solid oxygen later identified as O
8. Cacace's team think that O
4 probably consists of two dumbbell-like O
2 molecules loosely held together by induced dipole dispersion forces.

Phases of solid oxygen

There are six known distinct phases of solid oxygen. One of them is a dark-red O
8 cluster. When oxygen is subjected to a pressure of 96 GPa, it becomes metallic, in a similar manner as hydrogen,^[11] and becomes more similar to the heavier chalcogens, such as tellurium and polonium, both of which show significant metallic character. At very low temperatures, this phase also becomes superconducting.

References

^ ^a ^b Ryan D. McCulla, Saint Louis University (2010). "Atomic Oxygen O(3P): Photogeneration and Reactions with Biomolecules".
^ "Out of Thin Air". NASA.gov. February 17, 2011.
^ Chieh, Chung. "Bond Lengths and Energies". University of Waterloo. Archived from the original on 14 December 2007. Retrieved 2007-12-16.
^ ^a ^b Chemistry Tutorial : Allotropes from AUS-e-TUTE.com.au
^ Stwertka 1998, p.48
^ ^a ^b ^c ^d Mellor 1939
^ Stwertka 1998, p.49
^ "Who is most at risk from ozone?". airnow.gov. Archived from the original on 17 January 2008. Retrieved 2008-01-06.
^ Paul Wentworth Jr., Jonathan E. McDunn, Anita D. Wentworth, Cindy Takeuchi, Jorge Nieva, Teresa Jones, Cristina Bautista, Julie M. Ruedi, Abel Gutierrez, Kim D. Janda, Bernard M. Babior, Albert Eschenmoser, Richard A. Lerner (2002-12-13). "Evidence for Antibody-Catalyzed Ozone Formation in Bacterial Killing and Inflammation". Science 298 (5601): 2195–2199. Bibcode:2002Sci...298.2195W. doi:10.1126/science.1077642. PMID 12434011.
^ Cotton, F. Albert and Wilkinson, Geoffrey (1972). Advanced Inorganic Chemistry: A comprehensive Text. (3rd Edition). New York, London, Sydney, Toronto: Interscience Publications. ISBN 0-471-17560-9.
^ Peter P. Edwards and Friedrich Hensel (2002-01-14). "Metallic Oxygen". ChemPhysChem 3 (1): 53–56. doi:10.1002/1439-7641(20020118)3:1<53::AID-CPHC53>3.0.CO;2-2. PMID 12465476. Retrieved 2007-12-16.

English Journal

Echinacea-Based Dietary Supplement Does Not Increase Maximal Aerobic Capacity in Endurance-Trained Men and Women.

Stevenson JL1, Krishnan S1, Inigo MM2, Stamatikos AD1, Gonzales JU2, Cooper JA1.
Journal of dietary supplements.J Diet Suppl.2016 May 3;13(3):324-38. doi: 10.3109/19390211.2015.1036189. Epub 2015 Aug 28.
PURPOSE: To determine if an echinacea-based dietary supplement (EBS) provided at two different doses (a regular dose (RD), 8,000 mg/day, vs. a double dose (DD), 16,000 mg/day) would increase erythropoietin (EPO) and other blood markers involved in improving aerobic capacity and maximal oxygen cons
PMID 26317662

Attenuation of Oxidative Damage by Boerhaavia diffusa L. Against Different Neurotoxic Agents in Rat Brain Homogenate.

Ayyappan P1, Palayyan SR1, Kozhiparambil Gopalan R1.
Journal of dietary supplements.J Diet Suppl.2016 May 3;13(3):300-12. doi: 10.3109/19390211.2015.1036186. Epub 2015 Aug 13.
Due to a high rate of oxidative metabolic activity in the brain, intense production of reactive oxygen metabolite occurs, and the subsequent generation of free radicals is implicated in the pathogenesis of traumatic brain injury, epilepsy, and ischemia as well as chronic neurodegenerative diseases.
PMID 26268727

Identification of products from canthaxanthin oxidation.

Mordi RC1, Walton JC2.
Food chemistry.Food Chem.2016 Apr 15;197(Pt A):836-40. doi: 10.1016/j.foodchem.2015.11.053. Epub 2015 Nov 12.
Canthaxanthin is a carotenoid that lacks pro-vitamin A activity but is known to have antioxidant activity. The products of its oxidation in oxygen were found to be mainly substituted apo-carotenals and apo-carotenones. The product profile resembles that obtained in the oxidation of β-carotene, exce
PMID 26617024

Japanese Journal

Modifications on the hydrogen bond network by mutations of Escherichia coli copper efflux oxidase affect the process of proton transfer to dioxygen leading to alterations of enzymatic activities

Kajikawa Takao,Kataoka Kunishige,Sakurai Takeshi
Biochemical and Biophysical Research Communications 422(1), 152-156, 2012-05-25
… This network transports protons in the four-electron reduction of dioxygen. …
NAID 80022542855

An O-centered structure of the trinuclear copper center in the Cys500Ser/Glu506Gln mutant of CueO and structural changes in low to high X-ray dose conditions

Komori Hirofumi,Sugiyama Ryosuke,Kataoka Kunishige,Higuchi Yoshiki,Sakurai Takeshi
Angewandte Chemie - International Edition 51(8), 1861-1864, 2012-02-12
… Right on CueO: The O-centered structure of the trinuclear copper center in a multicopper oxidase (CueO) was shown to be an intermediate of the four-electron reduction of dioxygen (see picture). …
NAID 120003959483

Related Pictures

★リンクテーブル★

リンク元	「酸素分子」「二原子酸素」「二酸素」「molecular oxygen」
拡張検索	「4-hydroxyphenylpyruvate dioxygenase」「4-hydroxyphenylpyruvic acid dioxygenase deficiencies」「procollagen-proline dioxygenase」「dioxygenase」「protocatechuate dioxygenase」