Geometric progression: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
← Older edit
en>David Eppstein
Undo spam and misinformation
en>Wcherowi
Reverted 1 edit by Wcherowi (talk): Oops, sorry. (TW)
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
'''Dioxygen complexes''' are [[coordination compound]]s that contain O<sub>2</sub> as a [[ligand]].<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref>  The study of these compounds is inspired by oxygen-carrying proteins such as [[myoglobin]], [[hemoglobin]], [[hemerythrin]], and [[hemocyanin]].<ref>S. J. Lippard, J. M. Berg “Principles of Bioinorganic Chemistry” University Science Books: Mill Valley, CA; 1994. ISBN 0-935702-73-3.</ref>  Several [[transition metal]]s form complexes with O<sub>2</sub>, and many of these complexes form reversibly.<ref>Berry, R. E. "Reactivity and Structure of Complexes of Small Molecules: Dioxygen", Comprehensive Coordination Chemistry II, 2004, 1, 625-629.</ref>  The binding of O<sub>2</sub> is the first step in many important phenomena, such as [[cellular respiration]], [[corrosion]], and industrial chemistry. The first synthetic oxygen complex was demonstrated in 1938 with cobalt(II) complex reversibly bound O<sub>2</sub>.<ref>{{cite journal | author = Tokuichi Tsumaki | title = Nebenvalenzringverbindungen. IV. Über einige innerkomplexe Kobaltsalze der [[Salen ligand|Oxyaldimine]] | journal = [[Bulletin of the Chemical Society of Japan]] | year = 1938 | volume = 13 | pages = 252–260 | doi = 10.1246/bcsj.13.252}}</ref>
Next - GEN Gallery is a full incorporated Image Gallery plugin for Word - Press which has a Flash slideshow option. Affilo - Theme is the guaranteed mixing of wordpress theme that Mark Ling use for his internet marketing career. Step-4 Testing: It is the foremost important of your Plugin development process. Dead links are listed out simply because it will negatively have an influence on the website's search engine rating. In the most current edition you can customize your retailer layout and display hues and fonts similar to your site or blog. <br><br>Most Word - Press web developers can provide quality CMS website solutions and they price their services at reasonable rates. Best of all, you can still have all the functionality that you desire when you use the Word - Press platform. This plugin allows a blogger get more Facebook fans on the related fan page. By purchasing Word - Press weblogs you can acquire your very own domain title and have total command of your web site. But in case you want some theme or plugin in sync with your business needs, it is advisable that you must seek some professional help. <br><br>The entrepreneurs can easily captivate their readers by using these versatile themes. Browse through the popular Wordpress theme clubs like the Elegant Themes, Studio Press, Woo - Themes, Rocket Theme, Simple Themes and many more. I've applied numerous Search engine optimization-ready Word - Press themes and I can say from knowledge that I consider the Genesis Search engine marketing panel one particular of the simplest to use. The first thing you need to do is to choose the right web hosting plan. After that the developer adds the unordered list for navigations. <br><br>The primary differences are in the plugins that I install, as all sites don't need all the normal plugins. I have compiled a few tips on how you can start a food blog and hopefully the following information and tips can help you to get started on your food blogging creative journey. Enterprise, when they plan to hire Word - Press developer resources still PHP, My - SQL and watch with great expertise in codebase. Contact Infertility Clinic Providing One stop Fertility Solutions at:. The Pakistani culture is in demand of a main surgical treatment. <br><br>There is no denying that Magento is an ideal platform for building ecommerce websites, as it comes with an astounding number of options that can help your online business do extremely well. Automated deal feed integration option to populate your blog with relevant deals. It's not a secret that a lion share of activity on the internet is takes place on the Facebook. If this is not possible you still have the choice of the default theme that is Word - Press 3. For your information, it is an open source web content management system If you adored this post and you would such as to receive even more information relating to [http://247url.info/wordpress_dropbox_backup_735196 wordpress backup] kindly go to our own website. .
 
==Mononuclear complexes of O<sub>2</sub>==
O<sub>2</sub> binds to a single metal center either “end-on” ([[hapticity|η<sup>1</sup>-]]) or “side-on”  (η<sup>2</sup>-). The bonding and structures of these compounds are usually evaluated by single-crystal [[X-ray crystallography]], focusing both on the overall geometry as well as the O---O distances, which reveals its [[bond order]].
:[[Image:TMdioxygenCmpx.png|220px|center]]
 
===Complexes of η<sup>1</sup>-O<sub>2</sub> ligands===
O<sub>2</sub> [[adduct]]s derived from [[cobalt]](II) and [[iron]](II) [[porphyrin]] complexes and related anionic ligands exhibit this bonding mode. Myoglobin and hemoglobin are famous examples, and many synthetic analogues have been described that behave similarly. Binding of O<sub>2</sub> is usually described as proceeding via [[electron transfer]] from the metal(II) center to give [[superoxide]] (O<sub>2</sub><sup>-</sup>) complexes of metal(III) centers.
 
===Complexes of η<sup>2</sup>-O<sub>2</sub> ligands===
η<sup>2</sup>- bonding is the most common motif seen in coordination chemistry of dioxygen.  Such complexes can generated by treating low-valent metal complexes with gaseous oxygen. For example, [[Vaska's complex]] reversibly binds O<sub>2</sub> (Ph = C<sub>6</sub>H<sub>5</sub>):
:IrCl(CO)(PPh<sub>3</sub>)<sub>2</sub>  +  O<sub>2</sub>  <math>\overrightarrow{\leftarrow}</math>  IrCl(CO)(PPh<sub>3</sub>)<sub>2</sub>O<sub>2</sub>
The conversion is described as a 2 e<sup>-</sup> [[redox]] process: Ir(I) converts to Ir(III) as dioxygen converts to peroxide.  Since O<sub>2</sub> has a triplet ground state and Vaska's complex is a singlet, the reaction is slower than when [[singlet oxygen]] is used.<ref>Selke, M. and Foote, C. S., "Reactions of Organometallic Complexes with Singlet Oxygen. Photooxidation of Vaska's Complex", J. Am. Chem. Soc., 1993, volume 115, pages 1166 - 1167.{{DOI|10.1021/ja00056a061}}</ref>
 
Complexes containing η<sup>2</sup>-O<sub>2</sub> ligands are fairly common, but most are generated using [[hydrogen peroxide]], not O<sub>2</sub>.  [[Chromate]] ([CrO<sub>4</sub>)]<sup>2-</sup>) can for example be converted to the tetraperoxide [Cr(O<sub>2</sub>)<sub>4</sub>]<sup>2-</sup>. The reaction of hydrogen peroxide with aqueous titanium(IV) gives a brightly colored peroxy complex that is a useful test for titanium as well as hydrogen peroxide.<ref>Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.</ref>
 
==Binuclear complexes of O<sub>2</sub>==
O<sub>2</sub> can bind to one metal of a bimetallic unit via the same modes discussed above for mononuclear complexes. A well-known example in nature is hemerythrin, which features a diiron carboxylate that binds O<sub>2</sub> at one Fe center. Dinuclear complexes can also cooperate in the binding, although the initial attack of O<sub>2</sub> probably occurs at a single metal. These binding modes include μ<sub>2</sub>-η<sup>2</sup>,η<sup>2</sup>-, μ<sub>2</sub>-η<sup>1</sup>,η<sup>1</sup>-, and μ<sub>2</sub>-η<sup>1</sup>,η<sup>2</sup>-. Depending on the degree of electron-transfer from the dimetal unit, these O<sub>2</sub> ligands can again be described as peroxo or superoxo.  In nature, such dinuclear dioxygen complexes often feature copper.<ref>Lewis, E. A. and Tolman, W. B., "Reactivity of Dioxygen-Copper Systems", Chemical Reviews 2004, 104, 1047-1076. {{DOI|10.1021/cr020633r}}.</ref>
:[[Image:DimetalDioxgenComplexes.png|420px|center]]
 
==Relationship to other oxygenic ligands and applications==
Dioxygen complexes are the precursors to other families of oxygenic ligands.  Metal oxo compounds arise from the cleavage of the O-O bond after complexation. [[Hydroperoxide|Hydroperoxo]] complexes are generated in the course of the reduction of dioxygen by metals.  The reduction of O<sub>2</sub> by metal catalysts is a key [[half-reaction]] in [[fuel cell]]s.
 
Metal-catalyzed oxidations with O<sub>2</sub> proceed via the intermediacy of dioxygen complexes, although the actual oxidants are often oxo derivatives.  The reversible binding of O<sub>2</sub> to metal complexes has been used as a means to purify oxygen from air, but cryogenic distillation of [[liquid air]] remains the dominant technology.
 
==References==
<references />
 
[[Category:Biochemistry]]
[[Category:Inorganic chemistry]]

Latest revision as of 21:18, 2 December 2014

Next - GEN Gallery is a full incorporated Image Gallery plugin for Word - Press which has a Flash slideshow option. Affilo - Theme is the guaranteed mixing of wordpress theme that Mark Ling use for his internet marketing career. Step-4 Testing: It is the foremost important of your Plugin development process. Dead links are listed out simply because it will negatively have an influence on the website's search engine rating. In the most current edition you can customize your retailer layout and display hues and fonts similar to your site or blog.

Most Word - Press web developers can provide quality CMS website solutions and they price their services at reasonable rates. Best of all, you can still have all the functionality that you desire when you use the Word - Press platform. This plugin allows a blogger get more Facebook fans on the related fan page. By purchasing Word - Press weblogs you can acquire your very own domain title and have total command of your web site. But in case you want some theme or plugin in sync with your business needs, it is advisable that you must seek some professional help.

The entrepreneurs can easily captivate their readers by using these versatile themes. Browse through the popular Wordpress theme clubs like the Elegant Themes, Studio Press, Woo - Themes, Rocket Theme, Simple Themes and many more. I've applied numerous Search engine optimization-ready Word - Press themes and I can say from knowledge that I consider the Genesis Search engine marketing panel one particular of the simplest to use. The first thing you need to do is to choose the right web hosting plan. After that the developer adds the unordered list for navigations.

The primary differences are in the plugins that I install, as all sites don't need all the normal plugins. I have compiled a few tips on how you can start a food blog and hopefully the following information and tips can help you to get started on your food blogging creative journey. Enterprise, when they plan to hire Word - Press developer resources still PHP, My - SQL and watch with great expertise in codebase. Contact Infertility Clinic Providing One stop Fertility Solutions at:. The Pakistani culture is in demand of a main surgical treatment.

There is no denying that Magento is an ideal platform for building ecommerce websites, as it comes with an astounding number of options that can help your online business do extremely well. Automated deal feed integration option to populate your blog with relevant deals. It's not a secret that a lion share of activity on the internet is takes place on the Facebook. If this is not possible you still have the choice of the default theme that is Word - Press 3. For your information, it is an open source web content management system If you adored this post and you would such as to receive even more information relating to wordpress backup kindly go to our own website. .

Retrieved from "https://en.formulasearchengine.com/index.php?title=Geometric_progression&oldid=264624"