pls provide me information on diff types of backbonding eg. ppi-ppi,ppi-dpi,dpi,ppi,,,,,etc

Pπ- Pπ bonding is called back bonding
In BF3molecule the 2P orbitals of each F atom are fully filled, while one of 2Porbital of the B atom is vacant. The two 2P orbitals involved in the formation of B-F bon and third 2P orbital is vacant, therefore
overlap laterally resulting in the transfer of electron pair of the fluorine atom into vacant orbitals of B-atom.
(B) The bonding its effective since energy level of both orbitals are same
(C) An additional Pπ- Pπbond is formed between Boron and Fluorine atom.
(D) As a result of the back donation of electrons from F to B, the deficiency of the Boron atom getscompensated and hence the of BF3decreases Lewis acidic nature
(E) The order of acidity is as follows BF3< BCl3< BBr3down the grp. back bonding decreases
(F) This type of bond has some double bond character & is known as back bonding.
(H) All three bond length are same due to delocalisation

If there is bonding between two atoms where one atom is having one vacant orbital and another is having one lone pair of electrons, then if this electron pair is donated to that respective vacant orbital then the bonding is called p(pie) - p(pie) or p(pie) - d(pie) depending on the orbital to which the electron pair is donated and from which the electron pair is donated. If both the orbitals are d orbitals, then bonding is called d(pie) - d(pie) bonding.These types of bonding are known as back- bonding also

Types of back-bonding are:P(pi) - P(pi)P(pi) - d(pi)d(pi) - d(pi) depending upon the orbitals involved in electron transfer/delocalisation. It changes hybridization of the species and thus its geometry is altered. It is a useful concept for JEE exam.