In previous studies, the mechanism for the reduction of Tetrachrorido platinum(IV) complex with 5ˊ-dGMP has been investigated. In this research, two platinum(IV) complexes [PtCl4(N-N)] (N-N = 4,4ˊ-dimethyl -2,2ˊ-bipyridine, A and 5,5ˊ-dimethyl -2,2ˊ-bipyridine, B) were considered and compared with PtIVdach (N-N = diamino cyclohexane) theoretically, by means of the Becke3LYP DFT functional calculations. The mechanism of two electron reduction were thoroughly followed for three compounds. The relatives Gibbs energies for all intermediate, transition states and products were calculated and compared. LUMO –HOMO energy gap was also determined, where this energy gap was 3.5ev in complexes A and B; and 4.5ev in PtIVdach. The overall calculated Gibbs energy for the formation of corresponding PtII complex is 30.0 kJ/mol in A, 28.5 kJ/mol in B and 43.2 kJ/mol in PtIVdach. Thus compounds A and B illustrate more favorability for the proposed two electron reduction, interestingly. The results demanded that the hydrogen bonds play a critical role in the stability of intermediates and transition states in PtIVdach. The effective parameters in the mechanism were also discussed.