N, N'-bis [o-(diphenylphosphino) benzylidene] ethylenediamine (P 2 N 2 ) can be reduced to the corresponding N, N'-bis-[o-(diphenylphosphino) benzyl] ethylenediamine (P 2 N 2 H 4 ) with excess NaBH 4 in refluxing ethanol. Interaction of Ru (OAc) 2 (Ph 3 P) 2 with one equivalent of P 2 N 2 H 4 in refluxing toluene gives the Ru (OAc) 2 (P 2 N 2 H 4 ) in high yield. IR, NMR and X-ray diffraction study of Ru((OAc) 2 P 2 N 2 H 4 reviews that the two acetate groups are monodenate coordinated and are in a mutually transposition. The compound as catalyst for homogeneous hydrogenation of acrylic acid have been investigated and the results indicate that title complex is more effective catalyst than the corresponding Ru-(OAc) 2 P 2 N 2 .