Why is #CO_2# a lewis acid?

1 Answer
Jul 13, 2018

Is it not an electron pair acceptor....?

Explanation:

Still the best way of making a #C-C# bond is to pour a Grignard reagent onto dry ice as shown...

#R-MgX + CO_2(s) stackrel("dry ether")rarr RCO_2^(-) + MgX_2(s)darr#

The carboxylate ion can be reprotonated by water work-up to give #RCO_2H#... And here carbon dioxide has accepted the formal pair of electrons conceived to be localized on the Grignard reagent...