Synthesis and characterization of Ru(IV) and Rh(I) complexes containing phenylimidazole ligands

Abstract

The reactions of chloro-bridged dimeric complexes [{(η³;η³-C₁₀H₁₆)Ru(μ-Cl)Cl}₂] and [{(η⁴-C₈H₁₂)RhCl}₂] with 1-(4-cyanophenyl)imidazole (CPI), 1-(4-nitrophenyl)imidazole (NOPI), 1-(4-formylphenyl)imidazole (FPI) and 1-(4-hydroxy-phenyl)imidazole (HPI) have been investigated. These reactions afforded complexes with the general formulations [(η³;η³-C₁₀H₁₆)RuCl₂ (L)] (L = CPI, 1; NOPI, 2; FPI, 3; HPI, 4) and [(η⁴-C₈H₁₂)RhCl(L)] (L = CPI, 5; NOPI, 6; FPI, 7; HPI, 8). Resulting complexes have been characterized by analytical and spectral (IR, ¹H and ¹³C NMR, UV–Vis) studies. Crystal structures of 2, 5 and 6 have been determined by single crystal X-ray diffraction analyses. Structural studies on the complexes 2, 5 and 6 revealed the presence of extensive inter- and intra-molecular C–H⋯X (X = O and Cl) and C–H⋯π interactions. Theoretical studies have been performed to authenticate the structures and NBO calculations to determine electronic properties of the complexes.