In BF3 back bonding is possible but not in BF4^- . How?
Dear User,
Back bonding is possible in BF3 due to the electron deficient nature of B. B in BF3 has an empty p orbitals which it utilises in back bonding. However, the electron deficient nature of BF3 is satisfied by a F- ion which eventually form BF4-. Now, BF4- doesnot have any vacant p orbital and therefore it cannot take part in back bonding.
Back bonding is possible in BF3 due to the electron deficient nature of B. B in BF3 has an empty p orbitals which it utilises in back bonding. However, the electron deficient nature of BF3 is satisfied by a F- ion which eventually form BF4-. Now, BF4- doesnot have any vacant p orbital and therefore it cannot take part in back bonding.