Spectral, structural and DFT studies of platinum group metal 3,6-bis(2-pyridyl)-4-phenylpyridazine complexes and their ligand bonding modes

New mononuclear half-sandwich platinum group metal (Ru, Rh and Ir) complexes were obtained by the reaction of arene or pentamethylcyclopentadienyl metal (Ru, Rh and Ir) complexes with 3,6-bis(2-pyridyl)-4-phenylpyridazine (Lph), yielding two sets of complexes. In one set (type-A), the metal bonds to the N1 and N2 atoms of the (Lph) ligand, and in the other (type-B), the metal bonds to the N3 and N4 atoms. The structures of these complexes were confirmed through X-ray crystallography and density functional theory calculations.