Synthetic, spectral and structural studies of some homo and hetero binuclear arene ruthenium (II) polypyridyl complexes

Homo-hetero binuclear cationic complexes with the formulation [(η6-arene)RuCl(μ-dpp)(L)]+ (η6-arene = benzene; L = PdCl2 (1a); PtCl2 (1b), and η6-arene = p-cymene; L = PdCl2 (2a); PtCl2 (2b)), [(η6-arene)RuCl(μ-dpp)(L)]2+(η6-arene = p-cymene; L = [(η6-C6H6)RuCl] (2c), and [(η6-C10H14)RuCl] (2d)) were prepared. Molecular structure of the representative homo binuclear complex [{(η6-C10H14)RuCl}(μ-dpp){(η6-C10H14)RuCl}](PF6)2 (2d) was determined crystallographically. Weak interaction studies on the complex 2d revealed stabilisation of the crystal packing by weak inter and intra molecular C–H⋯X (X = F, Cl, π) and π–π interactions. The C–H⋯F interactions lead to parallel helical chains and encapsulation of counter anion in self-assembled cavity arising from C–H⋯π and π–π weak interactions.