Complexes with general formula p,t-[Ru(CO)(PR3)(tren)]X-2 [R=Ph (1) or p-tol (2); tren=tris(2-aminoethyl)amine; X=Cl- or PF6-] were prepared from [RuCl2(CO)(dmf)(PR3)] by direct reaction with tren. The complexes were fully characterized by NMR (H-1, P-31{H-1}, HMBC H-1-P-31), FTIR and ESI-MS spectroscopy, elemental analysis, and the structures of p,t-Ru(CO)(PPh3)(tren)(2) (1 center dot PF6) and p,t-[Ru(CO)(P{p-tol}(3))(tren)]Cl-2 (2 center dot Cl) were determined by X-ray diffraction. The water soluble complexes 1 center dot Cl and 2 center dot Cl were tested as antimicrobial agents against Gram (+) and Gram (-) bacteria with the latter showing superior activity than the approved antimicrobial agent chloramphenicol in one of the strains. [GRAPHICS]