Three diamine-bis(diphenylphosphinobutane)ruthenium(II) complexes, isolated from the reaction of [Cl2Ru(dppb)] with diamines viz., 2,2-dimethyl-1,3-diamnopropane, 1,2-diaminocyclohexane and 1,8-diaminonaphthalene are reported. The synthesized complexes have been characterized on the basis of various physico-chemical studies viz., EDX, IR, FAB-MS, UV/Vis, NMR, TG-DTG and EXAFS studies. 31P NMR investigations confirm that the complex 3 is in cis form while the complexes 1-2 appear in trans form. The structure of complex 3 has been additionally determined by single crystal X-ray diffraction showing solvated dichloromethane. Furthermore, complex 3 crystallizes as monoclinic unit cell with P2(1)/n space group. © 2014 Elsevier B.V. All rights reserved.