Term
| Give 2 charcteristics all ortho-para directors share |
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Definition
1. all are activating groups
2. all electron donating |
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Term
O -
NR2
NH2
OH
.tell whether these are:
1.strongly ,moderate, weakly activating OR deactivating
include why
2.ortho- para OR meta directors |
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Definition
STRONGLY activating ortho- para directors
why: they all contain lone pairs , i.e. unshared electron pairs that exist outside the ring |
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Term
| the most activating ortho- para f directors tend to have |
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Definition
| electron pairs that exist outside the ring |
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Term
which is more activating?
OH vs OCH3 |
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Definition
OH b/c:
it has an unshared electron pair |
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Term
1.amides, OCOR, CH3O-
vs
2.R (alkyl), C6H5
Both of these grps are activating but which set is stronger? |
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Definition
amides, carboxylic acid, CH3O-
are moderatly activating
while R (alkyl), C6H5 are the weakest activating grps
(these have no lone pairs, which can make resonance structures) |
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Term
put these in order from most deactivating to least deactivating
Cl-
I-
Br-
F- |
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Definition
Most deactivating= most electronegative
F-
Cl-
Br-
I-
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Term
-X
halogens
Tell whether:
1.stong/moderate/weak
activating
2. o/p or meta directors |
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Definition
Halogens are weakly deactivating
& ortho para directors
they can donate an unshared pair of electrons (as shown by resoance structures) by indutive effect. |
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Term
| what is the inductive effect? |
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Definition
if 'G' is an electronegative atom(a substitute on the benzene ring) than Carbon then the:
ring: + charge
G : -charge
ring will have postive charge |
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Term
| electron contribution to benzene is greater by resoance or the indutive effect. |
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Definition
resonance
(structures allow the posotive charge to go on the substitute , aka NOT IN THE RING) |
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Term
order these grps from most electron donating to least electron donating
OR, -NH2, OH, -NR2 |
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Definition
most e donating= more lone pairs
-NH2,-NR2
OH
OR
X (weakly deactating=electronegative) |
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Term
N02, NR3+,CF3,-CCl3
.tell whether these are:
1.strongly ,moderate, weakly activating OR deactivating
2.ortho- para OR meta directors
why? |
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Definition
strongly deactivating/meta directors
the combined electonegativities of these atoms, has an inductive effect,causes positive charge to be in the ring. |
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Term
which is more deactivating
tell whether these are:
CN or CF3 why? |
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Definition
CF3
(F is more electronegative than N) |
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Term
which is more deactivating
-CCl3 or -SO3H? |
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Definition
-CCl3
more electronegative |
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Term
COOH
COOR
COHR
COR2
tell whether these are:
1.strongly ,moderate, weak activating OR deactivating
2.ortho- para OR meta directors
why? |
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Definition
moderatly deactivating
b/c carbonyl grp provides resonace structures in which electrons are taken away from ring (giving it a positive charge) |
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