62
Lokesh Verma
·2008-11-18 19:49:20
Conditions:
- charge/ +charge/ free radical/ lone pair in conjugation with pi bond
pi in conjugation with sigma bond
1
kushal khandelwal
·2008-11-18 19:51:21
A chemically conjugated system is a system of atoms covalently bonded with alternating single and multiple (e.g. double) bonds (e.g., C=C-C=C-C) in a molecule of an organic compound.
This system results in a general delocalization of the electrons across all of the adjacent parallel aligned p-orbitals of the atoms, which increases stability and thereby lowers the overall energy of the molecule.
1
kushal khandelwal
·2008-11-18 19:54:26
Alternate positions of molecule having pi bond /charge/ +charge/ odd electron/ lone pair of electrons are known as conjugate positions .
Compounds having atleast 2 conjugate positions are said to be conjugated compounds.
1
Surbhi Agrawal
·2008-11-18 19:55:03
what does it mean when it is said that system is conjugated?.. does it mean that... delocalisation of pi electrons can take place????
62
Lokesh Verma
·2008-11-18 19:55:42
system is conjugated means it has alternate structure..
which u can say leaving one atome..
1
kushal khandelwal
·2008-11-18 20:00:38
it means at its alternate positions it has pi bond /charge/ +charge/ odd electron/ lone pair separated by a sigma bond.
ex
C=C-C=C-C
1 3
here at 1 and 3 rd positions we have alternate pi bond.
These pi bond are in conjugation.
The pi electrons delocalize themselves to give the next conjugated structure.
1
Surbhi Agrawal
·2008-11-18 20:05:20
ohk.. so the above system is not a conjugate system!
1
Surbhi Agrawal
·2008-11-18 20:11:39
plz correct me if i m wrong...
62
Lokesh Verma
·2008-11-18 20:21:07
This is conjugate system.. bcos there are 2 alaternate pi bonds.. i mean separated by one sigma bond..
It is not necessary that the ring is completed!
If the ring is completed, then it will be in resonance.
1
Surbhi Agrawal
·2008-11-18 20:35:43
but there are continuously two sigma bonds (indicated by arrows)....
1
Surbhi Agrawal
·2008-11-18 20:43:09
ohk so as here there are more than 2 conjuate positions... this system is a conjugate system!
62
Lokesh Verma
·2008-11-18 20:59:56
yes exactly :)
basically if the electrons can move and form (*newer) structures.