Department of Chemistry, P. D. Women’s College, Jalpaiguri-735 101, West Bengal, India E-mail: udaygrwlla@gmail.com Manuscript received online 04 December 2019, revised 06 December 2019, accepted 09 December 2019 The catalytic properties of the mononuclear non-heme iron(III) complexes with N4 -donor ligands containing N,N´-bis(2- pyridylmethyl)-diamine moiety (diamines used are, 1,2-cyclohexanediamine in complex 1 and ethane-1,2-diamine in complex 2) have been investigated in the epoxidation of alkenes using green and environmentally benign hydrogen peroxide (H2O2 ) and tert-butyl hydroperoxide (tBuOOH) as terminal oxidants at room temperature. The analysis of the results obtained in the oxidation of cyclohexene suggests the involvement of radical-based pathway in the catalytic epoxidation reaction. The cataytic efficiency in terms of the yield of the oxidation products is found to be strongly dependent on the nature of the diamine moiety in the catalyst and the oxidant.