species which is capable of donating a pair of electrons
1 of 15
electrophile
species which is capable of accepting a pair of electrons
2 of 15
Homolytic cleavage
splitting of covalent bond in way that 1 electron goes to each atom
3 of 15
Heterlytic cleavage
splitting of covalent bond in such way that both electrons go to 1 atom - ie what happens in mechanisms
4 of 15
Electronic effects apply to what type of bonds
sigma bonds only
5 of 15
+I group
have electron releasing effects. stabilize the structure . ALKYL groups . they push electrons towards C center
6 of 15
-I groups
have electron withdrawing effects due to being more e neg. destabalize structure. all groups which are not alkyl groups . they pull electorns from the C centre.
7 of 15
Mesomeric effects apply to what type of bonds
Pi bonds ( ie double bonds ) (C=O/C=C)
8 of 15
+M groups
are stabilizing- electron releasing, donate a pair of electrons to push electrons around (normally a ring), examples alkene (C=C) phenyl =, aklyne , amine (NH2- N donates :) ether, alcohol (OH donates :)
9 of 15
-M groups
destabilizing, electron withdrawing, pulls electrons towards self, arrow from = towards the o atom , this causes electrons and (charge to move around thew ring) , aldehydes, ketones, COOH, ester, anything with carbonyl , nitriles and NO2
10 of 15
How to increase nucleophilic strength?
1. increase number of +I groups, since are e releasing 2. if nuc is negatively charged it is a stronger nuc 3. decrease electroneg groups (-I groups - as they are e withdrawing and will pull e from nuc site)
11 of 15
weakest Nucleophile
water
12 of 15
Electrophilic strength
1. increase electroneg groups (-I groups as they are e withdrawing - electrophile needs to have area of LOW E DENSITY) 2. decrease alkyl groups which are e releasing- increase e density
13 of 15
what effect do +I groups have on acidity
decrease acidity - since will make more stable - and less likely to donate proton
14 of 15
what effect do -I groups have on acidity
increase acidity - since destabilize - more likely to give up/donate proton
15 of 15
Other cards in this set
Card 2
Front
electrophile
Back
species which is capable of accepting a pair of electrons
Comments
No comments have yet been made