Question

11). (12 pts) For each pair of nucleophiles, CIRCLE the one that is more nucleophilic, and provide a short explanation for your choice. A) CH.CH.CH OH and CH CH CH NH B) CH-OH and C H-O"Nat C) I and Br" D) (CH-CH2),P (Triethylphosphine) and (CH-CH2),N (triethylamine)

Answer 1

Ans - Nucleophile - $t is a chemical species which donates it electron pair to electrophilic centre to form a chemical bond, 4t can be a anion or a neutral molecules. So, Nucleo bhile is a lewi's base C donate electron pair). @ 119 12C11,014 and Mzc112 41. Wit The electronegativity of Nitrogen atom in -NH2 group is less than oxygen atem. Electronegativity of otem means it can alreact shared pair of election towards itself and has dess tendency to donate elections. As electronegativity of Nitrogen atom is less than oxygen so it can easily donated sits lectron pour to a electrophilic centre. So, -NH₂ group is a better nucleophile thon -oh group. Se, 443CH24H, NHQ is better Nucleophile. ® GHSOH and Coltsonat As we know that an anion is always a better nucleophile Cho is a conjugate base so it is a better nucleophile than the neutral molecule ColoH and also the election dersity on Colgo is greater CH SO Nat is better nucleophile than GHOH

© I and By As we know that as we move down the group a size of atom increases and electronegativity decreaser. Godine is leus electronegative than Bromine and therefore I can easily donate electron pair and is a better nucleophile Bro is more electronegative than I, can hold electrons tightly and is difficult to lose electrons. I is better nucleophile than Bro D (chache), P (triethylphosphine) and (CH3CH2)2N (teciethylamine) As the size of phosphorus alom is greater than the size of Nitrogen atom. [down the group size increases]. Bo, Due to steric condition the (LH₂ CH₂)₂N is bettent nucleophile thas (11₂ CH2 ) ;P. (CH₂ CH2)₂N is belter nucleophile than (CH₂ CH2)₂ P.