Ruthenium(II) carbonyl compounds with the 4'-chloro-2,2':6',2''-terpyridine ligand

Two ruthenium carbonyl complexes with the 4'-chloro-2,2':6',2''-terpyridine ligand (tpy-Cl, C₁₅H₁₀ClN₃), i.e. [RuCl(tpy-Cl)(CO)₂][RuCl₃(CO)₃] (I) [systematic name: cis-di-carbonyl-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ³N)ruthenium(II) fac-tricarbonyltri-chlorido-ruthenate(II)], and [RuCl₂(tpy-Cl)(CO)₂] (II) [cis-dicarbonyl-trans-di-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ²N¹,N^1')ruthenium(II)], were synthesized and characterized by single-crystal X-ray diffraction. The Ru^II atoms in both centrosymmetric structures (I) and (II) display similar, slightly distorted octa-hedral coordination spheres. The coordination sphere in the complex cation in compound (I) is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octa-hedral [Ru(CO)₃Cl₃]^- counter-anion. In the neutral compound (II), the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the Ru^II atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I) and (II), weak C-H⋯Cl inter-actions are observed.