What are the conditions for Back bonding?

 (1) Both of the atoms bonded with back Bonding are must be present in 2nd-2nd or 2nd-3rd period.

(2) One of the atoms has lone pair and another have vacant Orbital and direction of back Bonding depends upon vacant Orbital.

(3) The donor atom must have localized donatable electron pair. In general these are later half second period P - block elements (F, O, N and C).

(4) The acceptor atom must have low energy empty orbital which generally are np or nd orbitals. Small and similar sized orbital’s favour overlap.

EFFECTS OF BACK BONDING:

(1) It always leads to an increase in bond order between the participating atoms.

(2) It always leads to an increase in bond strength between participating atoms.

(3) It always leads to a decrease in bond length between participating atoms.