Ferrocene: an exotic building block for supramolecular assemblies

Ferrocene (Fc), a classical organometallic complex, has found potential applications in ligand design, catalysis, and analytical, biological, medicinal and materials chemistry. In recent years, the use of Fc as a building block in supramolecular chemistry has emerged. The molecular shape, size, and hydrophobicity of Fc make it an ideal guest for a variety of macrocyclic host molecules to form stable host-guest complexes. The vertical distance (3.3 angstrom) between two cyclopentadienyl rings and molecular ball bearing property in Fc support the formation of intramolecular pi-pi stacking, H-bonding and metallophilic interactions between two appropriate substituents in 1,n '-disubstituted ferrocenes. Along with these molecular features, the rigidity along with rotational flexibility, redox reversibility and oxidation-triggered tunable hydrophobicity of Fc have led to its use as an exotic building block for the development of a wide range of supramolecular assemblies such as smart molecular receptors, intricate metal-organic assemblies, supramolecular polymers, and gels including out-of-equilibrium assemblies and metal nanoparticle assemblies. This review highlights the concepts behind the design and development of these assemblies, where the Fc unit has a direct and defined role in their formation and function. The use of Fc in supramolecular assembly is still a relatively young field and set to be the subject of increasing research interest towards the development of fascinating supramolecular structures with tailored properties and programmable functions towards applications in materials and biological sciences. Beyond organometallics, ferrocene supports a range of noncovalent interactions for the development of host-guest assemblies, molecular receptors, supramolecular polymers, gels, metal-organic, out-of-equilibrium and metal nanoparticle assemblies.

Automated summary

Ferrocene has potential applications in various fields such as ligand design, catalysis, analytical chemistry, biological chemistry, medicinal chemistry, and materials chemistry. It can be used as a building block in supramolecular chemistry, forming stable host-guest complexes with different macrocyclic host molecules. The unique properties of ferrocene make it suitable for the development of smart molecular receptors, metal-organic assemblies, supramolecular polymers, gels, and metal nanoparticle assemblies.