Q 11-11-42 E-c - Organic Chemistry (Mcmurry)

Question

Which reactant in each of the following pairs is more nucleophilic? Explain.  

a) BF₃ or F^-

Step-by-Step Solution

Answer

F^- 

Nucleophile

The nucleophiles are the negatively charged ions or neutral species that have a lone pair of electrons and are ready for bonding.

Rules to identify more nucleophilic species

1. Nucleophile attacking the same atom then nucleophilicity is same as basicity that more basic species is more nucleophilic in nature.
2. Nucleophilicity increases in going down in a group of the periodic table.
3. A negatively charged nucleophile is more nucleophilic than a neutral nucleophile due to a negative charge.

More nucleophiles among BF 3 or F -

On the basis of:

Rule3: A negatively charged nucleophile is more nucleophilic than a neutral nucleophile due to a negative charge.

BF₃ is not a nucleophile even B(Boron) have empty d orbitals to gain electrons rather than to give electrons which nucleophile do. 

F^- is more nucleophilic than BF₃