| Author |
Message |
![[Post New]](/templates/default/images/icon_minipost_new.gif) 20 Apr 2008 23:07:37 IST
|
|
|
why are people talking about benzylic carbocation when the question asks A benzene ring with one carbon having a positive charge
|
It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars. Arthur C. Clarke
 
http://removesuperstition.blogspot.com/
|
this reply: 5 points
(with 1 
in 1 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
21 Apr 2008 06:07:10 IST
|
|
|
im saying only tat.....its benzene ring with a positive charge nd not benzylic cation !
|
Glitter Word Generator
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
21 Apr 2008 12:13:43 IST
|
|
|
ANSER IS B
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
21 Apr 2008 20:04:38 IST
|
|
|
I think its benzen ring which is more stable
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 07:40:15 IST
|
|
|
Arre yaar its not benzilic carbocation , it is benzene with a positive charge on one of the six carbons.........it is less stable than vinylic carbon with positive charge........Riya is right......answer is B
|
"Nenenthedhavano naake teleedu"
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 12:20:51 IST
|
|
|
Benzyl is more stable
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 13:34:46 IST
|
|
|
PLS SEE TIS : Stability of the carbocation increases with the number of alkyl groups bonded to the charge-bearing carbon. Tertiary carbocations are more stable (and form more readily) than secondary carbocations; primary carbocations are highly unstable because, while ionized higher-order carbons are stabilized by Hyperconjugation, unsubstituted (primary) carbons are not. Therefore, reactions such as the SN1 reaction and the E1 elimination reaction normally do not occur if a primary carbocation would be formed. An exception to this occurs when there is a carbon-carbon double bond next to the ionized carbon. Such cations as allyl cation CH2=CH-CH2+ and benzyl cation C6H5-CH2+ are more stable than most other carbocations. Molecules which can form allyl or benzyl carbocations are especially reactive.
the stability of a cation is
influenced by the electronegativity
of the atom bearing the positive charge.
The more electronegative the atom the less stable
the cation. A vinylic carbocation carries
the positive charge on an sp carbon, which is
more electronegative than an sp2
carbon of an alkyl carbocation.Therefore a primary vinylic carbocation is less stable than a primary alkyl carbocation.
also :
Carbocation
Stability | CH3(+) | ? | RCH=CH(+) | < | RCH2(+) | ? | RCH=CR(+) | < | R2CH(+) | ? | CH2=CH-CH2(+) | < | C6H5CH2(+) | ? | R3C(+) |
|---|
| Methyl |
| 1º-Vinyl |
| 1º |
| 2º-Vinyl |
| 2º |
| 1º-Allyl |
| 1º-Benzyl |
| 3º |
SOURCE : wikipedia , web.chem.ucla.edu/~harding/tutorials/cc.pdf , http://www.cem.msu.edu/~reusch/VirtualText/special1.htm
pls evry 1 giv ur views .............
|
Glitter Word Generator
|
this reply: 5 points
(with 1
in 1 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 15:52:33 IST
|
|
|
isnt the benzene ring with one c having a positive charge a benzilic cation ??? unless u remove a h from one of the c u dont get benzene with a c havin +ve charge ???
isnt it resonamce stabilized which is just not another effect cmon it is of the order of 100kj
definitely benzilic carbocation is more stable than vinylic as it has more resonance structures .
POINT OUT THE DIFFERENCE BETWEEN BENZENE WITH ONE C AS +VE CHARGE N BENZILIC CARBOCATION
|
COPYRIGHT :
The copyright for the facts written above is held by x4
no part of the facts may be reproduced , stored in ur memory , or transmitted by any means without pror written permission from x4
****VIOLATERS ARE LIABLE FOR PROSECUTION UNDER THE " X4 GOIIT ACT 2008 ".**** |
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 18:06:36 IST
|
|
|
i think BENZENE WITH ONE C AS +VE CHARGE means one of the carbons of the ring has positive
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 18:22:35 IST
|
|
|
for those of you who dont know what is benzylic carbocation , phenylic carbocation,vinylic carbocation here are they : :
|
this reply: 12 points
(with 2
in 3 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
22 Apr 2008 18:27:20 IST
|
|
|
phenyl carbocation is the most unstable coz order of stability of c-cations is something like-
benzyl>allyl>tertiary>secondary>primary>methyl>vinyl>phenyl...i suppose im right...if im wrong plz supply me with the rite answer
|
It doesn't work to leap a twenty-foot chasm in two ten-foot jumps.
There are three kinds of people; those that make things happen, those that watch things happen and those who don't know what's happening.
|
this reply: 2 points
(with 0
in 1 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
26 Apr 2008 13:46:14 IST
|
|
|
It is vinyl.....
the simple expln is tat it is bcoz..
the sp2 carbons has nw changed to sp carbon which hav the character of showing 180 * bond angle...
this is possible in vinyl cation nd is not in phenyl due to constrains......
nd also the resonance effest is not predominant in phenyl as the positive charge is makin a vacant p orbital nd it destablises the resonance effect in the remaining p orbitals.....this is also in case of vinyl where too the p orbitals make a gud difference.......so with this resonance concept one cant decide the stability in this case...
|
Glitter Word Generator
|
this reply: 2 points
(with 0
in 1 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
|
|
Moderation Team
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
![[Thumb - benzyl.JPG]](/upload/2008/4/22/c540246d305804f6494fa22c8523867c_25858.JPG_thumb)
![[Thumb - phenyl.JPG]](/upload/2008/4/22/7385147a2842eea8f5abdbb92ecea8a3_25858.JPG_thumb)
![[Thumb - vinyl.JPG]](/upload/2008/4/22/cc5069a2dcee87b34100eb99dc018f40_25858.JPG_thumb)
