Chlorogenation of pyrrole-based on di(pyridyl)pyrrolide ligand and synthesis of its ruthenium carbonyl complexes

The treatment of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (HL1) and PhICl2 as halogenation reagent generated monochloro-pyrrole HL2, dichloro-pyrrole HL3 and penta-chloro L4. The reaction of HL3 with [Ru(CO)2Cl2]n gave diruthenium(I) complex [Ru2(μ-κ2N,N′:κ1N″-L3)2(CO)4] (1) and monoruthenium(II) complex [Ru(κ3N,N′,N‴-L3)(κ2N,N′-L3)(CO)] (2). All these newly synthesized compounds were fully characterized by 1H NMR, IR, UV–Vis spectra, elemental analyses and X-ray diffraction study. The structural analysis shows that dichloro-pyrrole L3− acts as chelating and bridging ligand to coordinate two ruthenium atoms in 1, and acts as bidentated and tridentated ligand in 2.