Complexes: kinetics and mechanism, Chemistry

Assignment Help:

Electron transfer is the easiest type of redox process, an example being

1810_Untitled.png

A majority of reactions of that type are very fast, but oxidation by some complexes (especially of CoIII) is much slower. In an inner sphere process, the coordination sphere of one complex is substituted by a ligand bound to the other complex, which then reacts as a bridge and can be transferred in the mean while the redox process. As isotopic labeling studies give that the oxidation of aqueous Cr2+ with [CoIII(NH3)5Cl]2+ proceeds via a bridged species Cr-Cl-Co, the

chlorine not exchanging with free labeled Cl- in solution but remaining collide to the kinetically inert CrIII product. An inner sphere mechanism needs one of the reactants to be substitutionally labile, and a ligand that can performs as a bridge. One test is to compare the rates of reaction with the ligands azide and (N bonded) thiocynanate NCS-; azide is usually better at bridging and so produces faster rates if the inner sphere route is operating.

 

The outer sphere mechanism involves no disruption of the coordination of either complex, and is always needs as a route to electron transfer unless the inner sphere rate is faster. The Marcus theory displays that the rate of outer sphere transfer depends on:

 

(i) the orbital communication between the two metal centers involved, a factor that decreases roughly exponentially with the distance between them;

 

(ii) the change in metal-ligand distances giving from electron transfer, the effect that gives most of the activation energy for the reaction;

 

(iii) an enhancement term, which effect on the difference of redox potentials of the two couples involved.

 

 


Related Discussions:- Complexes: kinetics and mechanism

Matter, why the water is compound

why the water is compound

Calculations of volumetric analysis, Calculations of Volumetric analysis ...

Calculations of Volumetric analysis The subsequent points should be kept in mind while making calculations of volumetric exercises. (i) 1g equivalent mass of a substance car

APPLICATIONS OF INORGANIC COMPOUNDS, find two different substances and how ...

find two different substances and how they are produced. Once you have this information, look at their properties and how they are used, and explain how these properties affect th

Bond making or breaking, can u tell me what happens with ionic compounds wh...

can u tell me what happens with ionic compounds when heat is given??

Electrically conducting polymers, Q. Write short note on "Electrically cond...

Q. Write short note on "Electrically conducting polymers". Ans. electrically conducting polymers: Many synthetic organic polymers have been found to possess high electrical c

Mixture, which solution is formed when iodine solution ,copper sulphate...

which solution is formed when iodine solution ,copper sulphate and caustic soda are mixed?

Dienes, assignment of 15 pages on dienes

assignment of 15 pages on dienes

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd