Reactions of the ruthenium complexes [Ru(κ 3 -tpy)(PPh 3 )Cl 2 ], [Ru(κ 3 -tptz)(PPh 3 )Cl 2 ] and [Ru(κ 3 -tpy)Cl 3 ] [tpy=2,2′:6′,2′′-terpyridine; tptz=2,4,6-tris(2-pyridyl)-1,3,5-triazine] with diphenyl-(2-pyridyl)-phosphine (PPh 2 Py) have been investigated. The complexes [Ru(κ 3 -tpy)(PPh 3 )Cl 2 ] and [Ru(κ 3 -tptz)(PPh 3 )Cl 2 ] reacted with PPh 2 Py to afford [Ru(κ 3 -tpy)(κ 1 -P-PPh 2 Py) 2 Cl] + (1) and [Ru(κ 3 -tptz)(κ 1 -P-PPh 2 Py) 2 Cl] + (2), which were isolated as their tetrafluoroborate salts. Under analogous conditions, [Ru(κ 3 -tpy)Cl 3 ] gave a neutral complex [Ru(κ 3 -tpy)(κ 1 -PPh 2 Py)Cl 2 ] (3). Upon treatment with an excess of NH 4 PF 6 in methanol, 1 and 2 gave [Ru(κ 3 -tpy)(κ 1 -P-PPh 2 Py)(κ 2 -P,N-PPh 2 Py)](PF 6 ) 2 (4) and [Ru(κ 3 -tptz)(κ 1 -P-PPh 2 Py)(κ 2 -P,N-PPh 2 Py)](PF 6 ) 2 (5) containing both monodentate and chelated PPh 2 Py. Further, 4 and 5 reacted with an excess of NaCN and CH 3 CN to afford [Ru(κ 3 -tpy)(κ 1 -P-PPh 2 Py) 2 (CN)](PF 6 ) (6), [Ru(κ 3 -tpy)(κ 1 -P-PPh 2 Py) 2 (NCCH 3 )](PF 6 ) 2 (7), [Ru(κ 3 -tptz)(κ 1 -P-PPh 2 Py) 2 (CN)]PF 6 (8) and [Ru(κ 3 -tptz)(κ 1 -P-PPh 2 Py) 2 (NCCH 3 )](PF 6 ) 2 (9) supporting hemi labile nature of the coordinated PPh 2 Py. The complexes have been characterized by elemental analyses, spectral (IR, NMR, electronic absorption, FAB-MS), electrochemical studies and structures of 1, 2 and 3 determined by X-ray single crystal analyses. At higher concentration level (40μM) the complexes under investigation exhibit inhibitory activity against DNA-Topo II of the filarial parasite S. cervi and 3 catalyses rearrangement of aldoximes to amide under aerobic conditions.