A Ruthenium–Iron Bimetallic Supramolecular Cage with D4 Symmetry from a Tetrapyridyl Iron(I) Metalloligand

The novel iron(I) sandwich compound [Cp*Fe(η4-C4Py4)] (1) was prepared and characterized by various methods, including X-ray crystallography. Coordination-driven self-assembly of a diruthenium acceptor with the tetrapyridyl metalloligand [Cp*Fe(I)(η4-C4Py4)] led to a D4-symmetric three-dimensional M4L2 tetragonal supramolecular cage. This cage was characterized by IR and high-resolution electrospray ionization mass spectrometry. Its solid-state structure was confirmed by X-ray crystallography, showing a novel D4 cage system.