Is ammine strong ligand? Can NH3 act both as strong and weak ligand according to the situation? Please explain.
Why does Ni form outer orbital complex whereas Cr form inner orbital complex? Is it because there aren't 2 orbitals free in d in complex of Ni— so d²sp³ cannot be formed (no matter if the ligand is weak or strong)?
NH3 is a ligand with medium field strength. This is because its sigma donating capability is not very strong, and more importantly, it is neither a pi acceptor non a pi donor. That is why NH3 ligand is located at middle of the “Spectrochemical Series” for ligand strength.
If central atom is of 3d series, If cordination number is 6 (octahedral) and having +2 oxidation state then it is weak ligand and in +3 oxidation state it is strong ligand.If cordination number is 4 (tetrahedral) then it is weak ligand.
If central atom is of 4d and 5d series,It will behave as strong ligand in any condition.