Question

NH or Et,P-H v soro PHz or H,S в с D E F Which compound in each pair will be the more powerful nucleophile? Structure A or B? Structure Cor D? Structure E or F?

Answer 1

Nucleophilicity is the ability to donate electron to electron deficit species Electrophile (E+). It depends on how easily it displace other group in nucleophilic reactions.

Hence lower electronegativity and highly polarizable groups are powerful nucleophile with higher Nucleophilicity.

Fixed Posts Between, structure A and B .. . Structure Nh is more powerful (A) held Nucleophile because the alkyl groups are held back . Hence there is no steric hindrance to approching ! £t. . But in the bulky ethyl group dues repulsion to incomming | H+, Jhus nucleophilicity decreases. Vi is more powerful because it donate electrons more easily to E+ [as solen sulfur is less.. erative 7. And şi electronegative than than oxygen oxygen ] is more • Answer © Polarizible. e is better nucleophile than H₂ s . As electronegativity of P (2:1) is less than 5 (2.5). So 'p' donates. electron more easily to Et and PH₂ 1 Co-ordinate better. Answer-6.