Great question. While you are right in identifying that Cl has more lone pairs than O, that's not the only reason that drives the Li-O bond formation. This is primarily because of the following three reasons: 1. Hard-Soft Acid-Base Principle: Li is a hard acid and prefers to bond with hard bases like O, rather than Cl which is a soft bases. Oxygen’s high electronegativity and charge density make it a stronger bond partner for lithium. Therefore, favoring the Li-O bond. 2. Bond Strength and Stability: In this context, the Li-O bond is stronger and more stable than a Li-Cl bond. The lone pairs from oxygen’s are more reactive and bound tightly. Whereas, chlorine's lone pairs are more diffused. This makes the lone pairs from oxygen more effective in forming strong bonds with lithium. 3. Steric and Electronic Factors: In the slides you can see the structure of LTBA which has a bulky tert-butoxy groups. This essentially makes oxygen atoms more readily accessible to lithium. Finally, chlorine, despite having more lone pairs, is less nucleophilic due to its larger size and lower charge density. I hope this answers your question! Let me know if there's anything else you need help with. Cheers.
@@abdelhamidkhodja thank you it helped! just one thing, i read somewhere that nucleophilic strength increases with the increase in size (kindly correct me if im wrong), so hows o more nucleophilic than cl? is it due to electronegativity or smth, sorry if im being dense
@@khansa1485 While it is true that nucleophilic strength increases with size, especially when we are dealing with polar protic solvents where larger nucleophiles are less solvated and therefore more reactive. However, in this example, it is the specific reaction conditions that make O more nucleophilic than chlorine. O is more electronegative than Cl. The higher electron density on oxygen makes it a more reactive nucleophile, especially in polar aprotic solvents OR when forming bonds with hard acids like Li. You also mention how you read "that nucleophilic strength increases with the increase in size" - this concept is largely applicable in water/alcohols (polar protic solvents), where larger nucleophiles are less solvated and thus more nucleophilic. However, in the case of LTBA and acyl chlorides, the solvent environment and these specific reaction conditions make oxygen a more favorable nucleophile.
It's actually the electrons from water that go to the aluminum (not lithium), I misspoke during the lecture! Thanks for correcting me and sorry for the confusion.
why cant the cl from acid halide attack lithium of LTBA instead of O? i mean cl has more lone pairs than O?
Great question. While you are right in identifying that Cl has more lone pairs than O, that's not the only reason that drives the Li-O bond formation. This is primarily because of the following three reasons:
1. Hard-Soft Acid-Base Principle: Li is a hard acid and prefers to bond with hard bases like O, rather than Cl which is a soft bases. Oxygen’s high electronegativity and charge density make it a stronger bond partner for lithium. Therefore, favoring the Li-O bond.
2. Bond Strength and Stability: In this context, the Li-O bond is stronger and more stable than a Li-Cl bond. The lone pairs from oxygen’s are more reactive and bound tightly. Whereas, chlorine's lone pairs are more diffused. This makes the lone pairs from oxygen more effective in forming strong bonds with lithium.
3. Steric and Electronic Factors: In the slides you can see the structure of LTBA which has a bulky tert-butoxy groups. This essentially makes oxygen atoms more readily accessible to lithium. Finally, chlorine, despite having more lone pairs, is less nucleophilic due to its larger size and lower charge density.
I hope this answers your question! Let me know if there's anything else you need help with. Cheers.
@@abdelhamidkhodja thank you it helped! just one thing, i read somewhere that nucleophilic strength increases with the increase in size (kindly correct me if im wrong), so hows o more nucleophilic than cl? is it due to electronegativity or smth, sorry if im being dense
@@khansa1485 While it is true that nucleophilic strength increases with size, especially when we are dealing with polar protic solvents where larger nucleophiles are less solvated and therefore more reactive. However, in this example, it is the specific reaction conditions that make O more nucleophilic than chlorine. O is more electronegative than Cl. The higher electron density on oxygen makes it a more reactive nucleophile, especially in polar aprotic solvents OR when forming bonds with hard acids like Li.
You also mention how you read "that nucleophilic strength increases with the increase in size" - this concept is largely applicable in water/alcohols (polar protic solvents), where larger nucleophiles are less solvated and thus more nucleophilic. However, in the case of LTBA and acyl chlorides, the solvent environment and these specific reaction conditions make oxygen a more favorable nucleophile.
@@abdelhamidkhodja got it thank u sm!
im in year 11 and chemistry is my passion, really enjoyed the video mate
Thanks for the comment! Keep up the hard work and let me know if there's anything I can help you with. Cheers.
i was low key expecting an angry mustache guy rage against his students. I get something else.
Was so needed, I watched at work.
Same here man, I work at Odoo and watched this on company time (I'm a fraud).
@@MrGraphics sounds familiar
I'm sure the HR department would be thrilled to hear this
Better than most professors out there 👌🏼
"I am going to have to remove this from the recording."
This cured my depression
understand nothing but goes so hard
Average student experience
9:13 attacks the lithium or aluminum professor?
It's actually the electrons from water that go to the aluminum (not lithium), I misspoke during the lecture! Thanks for correcting me and sorry for the confusion.
@@abdelhamidkhodja no problem. You’re the best, professor!
@@ahmadmansour3432 No problem! YOU are the best student!
I'm in love with you
Hahaha, no, I am in love with you! Thanks for the comment!
Great 👍
Thank you! Cheers!
like your video prof
Glad to hear that, thanks!
Is this Professor single?
At the moment yes (that makes two of us) 😂
Who's watching in 2024?
Tf u talking about it was released 2 days ago