The chelating ligands 3-chloro-6-(3-pyridyl-1-pyrazolyl)pyridazine ($pp-Cl$) and 3,6-bis(3-pyridyl-1-pyrazolyl)pyridazine (bppp), were prepared by the condensation of pyridylpyrazole and 3,6-dichloropyridazine. The mononuclear complexes [($\eta^6$-arene)Ru($pp$-Cl)Cl]⁺ $\{\eta^6$-arene = C₆H₆ (1); 𝑝-${}^i$PrC₆H₄Me (2)}, [($\eta^5$-C₅Me₅)M($pp$-Cl)]⁺ {M = Rh (3); Ir (4)}, [($\eta^6$-arene)Ru($bppp$)Cl]⁺ $\{\eta^6$-arene = C₆H₆ (5); 𝑝-${}^i$PrC₆H₄Me (6)}, [($\eta^5$-C₅Me₅)M(bppp)]⁺ {M =Rh (7); Ir (8)} as well as the binuclear complexes [{($\eta^6$-arene)RuCl}₂(bppp)]²⁺ {$\eta^6$ -arene =C₆H₆ (9); 𝑝-$^i$PrC₆H₄Me (10)} and [{($\eta^5$-C₅Me₅)MCl}₂(bppp)]²⁺ {M = Rh (11); Ir (12)} have been synthesized from 3-chloro-6-(3-pyridyl-1-pyrazolyl)pyridazine ($pp-Cl$) or 3,6-bis(3-pyridyl-1-pyrazolyl)pyridazine (bppp) and the corresponding dimers [($\eta^6$-arene)Ru(𝜇-Cl)Cl]₂ and [Cp^∗M(𝜇-Cl)Cl]₂, respectively. All complexes were isolated as their hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV-visible spectroscopy. The molecular structures of [2]PF₆ and [7]PF₆ have been established by single crystal X-ray structure analysis.