Calculations of the EPR spectral parameter hyperfine coupling constants of Dipolar Metal Complexes [Co (CO)4] ,[Mn(CN)5NO]2 – ,[Mn(CN)4N]-, [Ni(CO)3H] have been carried out using density functional theory(DFT) with BHPW91, B3LYP, B3PW91, BLYP, BHLYP,BPW91, BP86, BHP86 functionals and the results obtained have been compared with experimental values. The results obtained from the density functional methods have been found in close agreement with the result obtained from the experiments. The performances of the different functionals for different transition metal complexes have been found different. The performance of the functional BP86 have been found better for [Ni(CO)3H], [Mn(CN)5NO]2– ;BHLYP for [Co (CO)4] and B3LYP for [Mn(CN)4N]- Dipolar Metal Complexes. We have not identified any such functional, the performance of which is excellent for calculation of EPR parameter hyperfine coupling constant for all transition metal complexes considered in this study.
Keywords – Density Functional Theory (DFT). Transition Metal Complexes, Hyperfine Coupling Constants.