4. (6p) (a) Which orbitals of PR3 phosphine ligand is taking part in octahedral complexes during o and n interaction with metal ions? (18p) (b) Show the molecular orbital energy level diagram for o and interaction of the orbitals in [Cr(PR3)] and calculate the bond degree of complex (Symmetry adapted orbitals for Ox: s= ais. px=tlo, py=tlu, p=tiu, de ej. dx23y2 = ex. dxy=tr. dxz = ty, dyz =) 5. (10p) (a) CO and NH3 are both strong-field ligands. However, experimental data show that in their complexes CO ligands cause higher splitting energy (A.) than NHs. How can you explain these result and give brief explanation about order of the strength of the ligands in spectrochemical series using Molecular Orbital Theory