NATURE OF THE LIGAND- SMALL LIGANDS APPROACH THE LIGANDS EASILY, SO THEY CAN CAUSE GREAT CRYSTAL FIELD SPLITTING. LIGANDS CONTAINING EASILY POLARISABLE ELECTRON PAIR WILL BE DRAWN MORE EASILY TO THE METAL ION.

FACTORS AFFECTING MAGNITUDE OF CRYSTAL FIELD SPLITTING

THE METAL ION WITH HIGHER OXIDATION STATE CAUSE LARGE CRYSTAL FIELD SPLITTINGTHAN IS DONE BY THE ION WITH LOWER OXIDATION STATE.

OXIDATION STATE OF METAL ION

THE EXTENT OF C.F.S FOR SIMILAR COMPLEXES OF METAL IN THE SAME OXIDATION STATE INCREASED BY ABOUT THIRTY TO FIFTY PERCENT ON GOING FROM FIRST TRANSITION SERIES TO THIRD TRANSITION SERIES. THE INCREASE IS ALMOST SAME AMOUNT AS GOING FROM SECOND TRANSITION SERIES TO THIRD TRANSITION SERIES. THIS MAY BE EXPLAINED ON THE BASIS THAT 4d ORBITAL IN COMPARISON TO 3d ORBITAL ARE BIGGER IN SIZE.AS A RESULT 4d ORBITAL INTERACT STRONGLY WITH LIGAND.

TYPES OF d- ORBITALS

CRYSTAL FIELD SPLITTING ENERGY OF TETRAHEDRAL COMPLEXES IS NEARLY HALF THE VALUE FOR OCTAHEDRAL COMPLEXES. IN OTHER WORDS, THE VALUE OF C.F.S.E FOR TATRAHEDRAL COMPLEXES IS SMALL AS COMPARED TO PAIRING ENERGY P.THE TETRAHEDRAL COMPLEXES ARE THEREFORE MOSTLY HIGH SPIN COMPLEXES.

GEOMETRY OF THE COMPLEX