Mononuclear complexes in- and out-[Ru(Cl)(trpy)(Hbpp)](+) (in-0, out-0; Hbpp is 2,2'-(1H-pyrazole-3,5-diyl)dipyridine and trpy is 2,2':6',2?-terpyridine) are used as starting materials for preparation of Ru-Zn heterodinuclear out-{[Ru(Cl)(trpy)][ZnCl2](mu-bpp)} (out-2) and heterotrinuclear in,in- and out,out-{[Ru(Cl)(trpy)](2)(mu-[Zn(bpp)(2)])}(2+) (in-3, out-3) constitutional isomers. Further substitution of the Cl ligand from the former complexes leads to Ru-aqua out,out-{[Ru(trpy)(H2O)](2)(mu-[Zn(bpp)(2)])}(4+) (out-4) and the oxo-bridged Ru-O-Ru complex in,in-{[Ru-III(trpy)](2)(mu-[Zn(bpp)(2)(H2O)]mu-(O)}(4+) (in-5). All complexes are thoroughly characterized by the usual analytical techniques as well as by spectroscopy by means of UV-vis, MS, and when diamagnetic NMR. CV and DPV are used to extract electrochemical information and monocrystal X-ray diffraction to characterize complexes out-2, in-3, out-3, and in-5 in the solid state. Complex out-3 photochemically isomerizes toward in-3, as can be observed by NMR spectroscopy and rationalized by density functional theory based calculations.