(i) Draw the geometrical isomer of complex [Pt(NH3)2Cl2]. (ii) On the basis of crystal field theory, write the electronic configuration for d4 ion if Δ0 < P. (iii) Write the hybridization and magnetic behaviour of the complex [Ni(CO)4]. (At. no. of Ni=28).

(i) Geometrical isomers of complex [Pt(NH3)2Cl2] is given in the figure (ii) On the basis of crystal field theory, for a d4 ion if, Δ0 < P. then complex is a high spin complex formed by association of weak field ligand with metal ion, As a result the fourth electron enters one of the eg orbitals, thereby, exhibiting the electronic configuration (iii) Outer electronic configuration of Ni atom in ground state and outer electronic configuration of Ni atom in Ni(CO)4 are given in the figure. Carbonyl, CO being a strong field ligand causes the pairing of up valence electrons in the Ni atom against the Hund's Rule of maximum multiplicity. This results in the formation of an inner orbitals complex, [Ni(CO)4]. Since, the complex [Ni(CO)4] has no unpaired electron, it is diamagnetic in nature and posses tetrahedral shape.