Metallosupramolecular Architectures Formed with Ferrocene-Linked Bis-Bidentate Ligands: Synthesis, Structures, and Electrochemical Studies

The self-assembly of ligands of different geometries with metal ions gives rise to metallosupramolecular architectures of differing structural types. The rotational flexibility of ferrocene allows for conformational diversity, and, as such, self-assembly processes with 1,1'-disubstituted ferrocene ligands could lead to a variety of interesting architectures. Herein, we report a small family of three bis-bidentate 1,1'-disubstituted ferrocene ligands, functionalized with either 2,2'-bipyridine or 2-pyridyl-1,2,3-triazole chelating units. The self-assembly of these ligands with the (usually) four-coordinate, diamagnetic metal ions Cu(I), Ag(I), and Pd(II) was examined using a range of techniques including ¹H and DOSY NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, X-ray crystallography, and density functional theory calculations. Additionally, the electrochemical properties of these redox-active metallosupramolecular assemblies were examined using cyclic voltammetry and differential pulse voltammetry. The copper(I) complexes of the 1,1'-disubstituted ferrocene ligands were found to be coordination polymers, while the silver(I) and palladium(II) complexes formed discrete [1 + 1] or [2 + 2] metallomacrocyclic architectures.

5-Ferrocenyl-2,2′-bipyridine ligands: synthesis, palladium(ii) and copper(i) complexes, optical and electrochemical properties

Two 5-ferrocenyl-2,2′-bipyridine ligands were synthesised using the palladium(0) catalysed Suzuki–Miyaura cross-coupling reaction. Palladium(ii) and copper(i) complexes of these ligands were synthesised and the optical and electrochemical properties of the complexes were compared to those of the “free” ligands.