Sierra Acai Company
Sierra Acai Company
Open 7 Days a Week
MonaVie Independent Distributor
Distributor Training
Shop Online
Enroll Now
Buy Wholesale and maintain an Active status for 2 months and we will refund your $39 Distributor Fee
Friends
Buy Wholesale and maintain an Active status for 2 months and we will refund your $39 Distributor Fee
16-September-2008 16:20:32 - reaction A free radical reaction is any chemical reaction involving free radicals. This reaction type is abundant in organic reactions. Two pioneering studies into free radical reactions have been the discovery of the triphenylmethyl radical by Moses Gomberg 1900 and the lead-mirror experiment 1 described by Friedrich Paneth in 1927. In this last experiment tetramethyllead is decomposed at elevated temperatures to methyl radicals and elemental lead in a quartz tube. The gaseous methyl radicals are moved to another part of the chamber in a carrier gas where they react with lead in a mirror film which slowly disappears. When radical reactions are part of organic synthesis the radicals are often generated from radical initiators such as peroxides or azobis compounds. Many radical reactions are chain reactions with a chain initiation step, a chain propagation step and a chain termination step. Reaction inhibitors slow down a radical reaction. Radical reactions occur frequently in the gas phase, are often initiated by light, are rarely acid or base catalyzed an are not dependent on polarity of the reaction medium 2. Reactions are also similar whether in the gas phase or solution phase 3. Kinetics The chemical kinetics of a radical reaction depend on all these individual reactions. In steady state the concentrations of initiating I. and terminating species T. are negligent and rate of initiation and rate of termination are equal. The overall reaction rate can be written as 4: \ rate = k_obsI^3/2 \, with a broken-order dependence of 1.5 with respect to the initiating species. The reactivity of different compounds toward a certain radical is measured in so-called competition experiments. Compounds bearing carbon-hydrogen bonds react with radicals in the order primary secondary tertiary benzyl allyl reflecting the order in C-H bond dissociation energy 4 Many stabilizing effects can be explained as resonance effects, an effect specific to radicals is the captodative effect. Reactions The most important reaction types involving free radicals are: Free radical substitution, for instance free radical halogenation and autoxidation. Free radical addition reactions Intramolecular free radical reactions substitution or addition such as the Hofmann-Löffler reaction or the Barton reaction Free radical rearrangement reactions are rare compared to rearrangements involving carbocations and restricted to aryl migrations. Fragmentation reactions or homolysis, for instance the Norrish reaction, the Hunsdiecker reaction and certain decarboxylations. For fragmentations taking place in mass spectroscopy see mass spectrum analysis. Electron transfer. An example is the decomposition of certain peresters by CuI which is a one-electron reduction reaction forming CuII, an alkoxy oxygen radical and a carboxylate. Another example is Kolbe electrolysis. Radical-nucleophilic aromatic substitution is a special case of nucleophilic aromatic substitution. Specific reactions involving free radicals are combustion, pyrolysis and cracking 5 References ^ Über die Darstellung von freiem Methyl Berichte der deutschen chemischen Gesellschaft A and B Series Volume 62, Issue 5 , Pages 1335 - 1347 Fritz Paneth, Wilhelm Hofz doi:10.1002/cber.19290620537 ^ Free Radical Reaction - from Eric Weisstein's World of Chemistry ^ March, Jerry 1985. Advanced Organic Chemistry, Reactions, Mechanisms and Structure, third ion, John Wiley Sons. ISBN 0-471-85472-7. ^ a b Advanced Organic Chemistry F.A. Carey R.J. Sundberg ISBN 0-306-41198-9 ^ Robert T. Morrison, Robert N. Boyd, and Robert K. Boyd, Organic Chemistry, 6th ion Benjamin Cummings, 1992, ISBN 0-13-643669-2 Retrieved from http://en..org/wiki/Free_radical_reaction Categories: Organic chemistry | Free radical reactions Views Article Discussion this page History Personal tools Log in / create account Navigation Main page Contents Featured content Current events Random article Search Go Search Interaction Community portal Recent changes Contact Donate to Help Toolbox What links here Related changes Upload file Special pages Printable version Permanent link Cite this page This page was last modified on 29 May 2008, at 21:3
39 Reasons to Drink Acai Juice Every Day
What is MonaVie - Watch the 8-minute video
Discovering MonaVie Video
The Power of You Video
Effects of MonaVie Active on Antioxidant Capacity in Humans
Log into your Wholesale MonaVie Account
So many of us do not eat a balanced diet, get enough sleep, have too much stress, or are impacted with toxins and pollutants. Drinking 2 ounces of MonaVie twice a day will help your body detoxify as well as build your immune system. Its the smartest thing you can do for yourself, so start today. Buying MonaVie through our company guarantees you support 7 days a week and, if you would like to share MonaVie with your family and friends we will guide you from start to finish.
1. Click on Enroll Now (30 - 55% off retail price)
2. Pay $39 for your Wholesale ID number.
3. NO minimum order required.
4. MonaVie is delivered to your door in 3 to 5 days.