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I've been working my tail off trying to fully understand nucleophillicty (nuc) and leaving group (LG) ability and I have a few questions.
Polar Protic solvent:
Nuc.: Going bottom to top in a column in periodic table means you lowered the principal quantum number, so the electrons occupy a smaller volume. Thus it is less stable aka more basic. This means that it will solvalize very easily with the solvent and therefore is a worse nucleophille??
LG: weak bases are the best, LG's with (+) charges are also good. How does the LG strength differ in polar, protic vs polar aprotic solvents??? I would think that because of solvation, the bigger the LG the better it is for a polar protic solvent...
Since SN1 only occurs in polar protic solvents, SN1 requires a strong nucleophile and a good LG?
Polar Aprotic:
Nuc.: the more basic the Nuc. the better it is, essentially the opposite of what is required in polar protic.
LG: I dont know what the criteion for a good LG would be in a polar protic.... HELP!
Since SN2 only works in polar aprotic solvents, you'd probably want an ok Nuc. and a decent LG?
Nuc. in SN1/SN2/E1/E2
SN1 always competes with E1, in order to get SN1 over E1 you would need a really good Nuc. but also a really bad base: ex. -CN? what other nuc. fit this category?
E2 can compete with SN2. You would need a really strong base and poor nucleophile to favor E2???
LG in SN1/SN2/E1/E2
Do LG's cause one mechanism to be favored over the other???
Polar Protic solvent:
Nuc.: Going bottom to top in a column in periodic table means you lowered the principal quantum number, so the electrons occupy a smaller volume. Thus it is less stable aka more basic. This means that it will solvalize very easily with the solvent and therefore is a worse nucleophille??
LG: weak bases are the best, LG's with (+) charges are also good. How does the LG strength differ in polar, protic vs polar aprotic solvents??? I would think that because of solvation, the bigger the LG the better it is for a polar protic solvent...
Since SN1 only occurs in polar protic solvents, SN1 requires a strong nucleophile and a good LG?
Polar Aprotic:
Nuc.: the more basic the Nuc. the better it is, essentially the opposite of what is required in polar protic.
LG: I dont know what the criteion for a good LG would be in a polar protic.... HELP!
Since SN2 only works in polar aprotic solvents, you'd probably want an ok Nuc. and a decent LG?
Nuc. in SN1/SN2/E1/E2
SN1 always competes with E1, in order to get SN1 over E1 you would need a really good Nuc. but also a really bad base: ex. -CN? what other nuc. fit this category?
E2 can compete with SN2. You would need a really strong base and poor nucleophile to favor E2???
LG in SN1/SN2/E1/E2
Do LG's cause one mechanism to be favored over the other???