PHOTOREDOX BEHAVIOR OF A TRINUCLEAR RU(III),RU(II),CO(III) COMPLEX-INDUCED BY METAL-TO-METAL CHARGE-TRANSFER EXCITATIONS

The trinuclear complex NC)Ru(II)(CN)(4)(mu-CN)Co(III)(NH3)(5)]Cl-2.2H( 2)O was prepared and characterized by IR and UV-Vis spectroscopy.; The aqueous complex shows two long-wavelength absorptions at lambda(max)= 647 and 372 nm which are assigned to Ru(III) to Ru(III) and Ru(II) to Co(III) MMCT transitions, respectively. Photolysis of the aqueous solu tion led to a redox decomposition. Co2+ was formed with phi=2X10(-4) a t lambda(irr)=577 and 0.18 at 366 nm. The electronic spectrum as well as the photoreactivity of the trinuclear complex are discussed on the basis of a Hush diagram which accommodates three redox-active metal ce nters.