halogen leaving group stability

[manutdfan]

Advertisement - Members don't see this ad

why is I a better leaving group than F?

is it because I is larger and can stabilize the - charge better?

 

[loveoforganic]

Yes. The charge is delocalized across the huge valence cloud.

 

[sv3]

is there a correlation between acidity and LG status?
like the stronger the acid the better the LG? (makes sense to me based on stabilities of conjugates but I don't want to make up a rule for myself if I'm just seeing coincidences)

 

[G1SG2]

is there a correlation between acidity and LG status?
like the stronger the acid the better the LG? (makes sense to me based on stabilities of conjugates but I don't want to make up a rule for myself if I'm just seeing coincidences)

Yeah, stability of the conjugate base is important for acidity. The more stable the conjugate base, the stronger the acid.

 

[sv3]

Yeah, stability of the conjugate base is important for acidity. The more stable the conjugate base, the stronger the acid.

Oh i meant between strong acids and Leaving group's....or is that what you mean and I'm not getting it?

 

[G1SG2]

Oh i meant between strong acids and Leaving group's....or is that what you mean and I'm not getting it?

Not sure if I fully understand what you mean by strong acids and leaving groups...the best leaving groups are usually weak bases, conjugates of strong (or relatively strong) acids. Is that what you meant?

 

[sv3]

Not sure if I fully understand what you mean by strong acids and leaving groups...the best leaving groups are usually weak bases, conjugates of strong (or relatively strong) acids. Is that what you meant?

Yuppers. Thanks. As in that's why I is better than F as a leaving group.....cause HI is a stronger acid than HF. Just making sure I wasn't screwing myself over with a false correlation.

 

[G1SG2]

Yuppers. Thanks. As in that's why I is better than F as a leaving group.....cause HI is a stronger acid than HF. Just making sure I wasn't screwing myself over with a false correlation.

Well, you know that HI is a stronger acid than HF because I- is much larger than F- and thus can stabilize itself much better than F-. So yes, if you want to think about it that way, you can. But it would also help to really conceptually think about why I would better leaving group than F (large ionic radius, stabilization, etc). But, yes you can do that.

 

[sv3]

Well, you know that HI is a stronger acid than HF because I- is much larger than F- and thus can stabilize itself much better than F-. So yes, if you want to think about it that way, you can. But it would also help to really conceptually think about why I would better leaving group than F (large ionic radius, stabilization, etc). But, yes you can do that.

Well that's what i meant.....aren't the reasons for HI being a strong acid the same as it for being a good leaving group?

Sorry i think i was unclear before.....i was checking to see if i was missing something conceptually b/c to me the same concepts are behind both, a strong acid and good leaving group.....my bad. I wouldn't just blanket memorize the stuff.......i've spent too god damn long studying to just memorize!

 

[G1SG2]

Well that's what i meant.....aren't the reasons for HI being a strong acid the same as it for being a good leaving group?

Sorry i think i was unclear before.....i was checking to see if i was missing something conceptually b/c to me the same concepts are behind both, a strong acid and good leaving group.....my bad. I wouldn't just blanket memorize the stuff.......i've spent too god damn long studying to just memorize!

Yeah, you got it. When's your test, btw?

 

[sv3]

august now
bumped it from july
that obvious i ain't ready eh?

how about you?

 

[G1SG2]

august now
bumped it from july
that obvious i ain't ready eh?

how about you?

Haha, was just asking. End of July for me.

 

[sv3]

Haha, was just asking. End of July for me.

that was my original (july 31). I wanted to first make it july 2, god what a mistake that woulda been. Now its looking like mid august or so. Not seeing this stuff for 8 years is really making it tough to remember. Ah well......