Persistent four-coordinate iron-centered radical stabilized by π-donation

Dinuclear iron carbonyl complex 2, which contains an elongated unsupported Fe-Fe bond, was synthesized by the reaction between Fe₂(CO)₉ and phosphinyl radical 1. Thermal Fe-Fe bond homolysis led to the generation of a four-coordinate carbonyl-based iron-centered radical, 3, which is stabilized by π-donation. Complex 3 exhibited high reactivity toward organic radicals to form diamagnetic five-coordinate Fe(ii) complexes.

A ferromagnetically coupled Fe42 cyanide-bridged nanocage

Self-assembly of artificial nanoscale units into superstructures is a prevalent topic in science. In biomimicry, scientists attempt to develop artificial self-assembled nanoarchitectures. However, despite extensive efforts, the preparation of nanoarchitectures with superior physical properties remains a challenge. For example, one of the major topics in the field of molecular magnetism is the development of high-spin (HS) molecules. Here, we report a cyanide-bridged magnetic nanocage composed of 18 HS iron(III) ions and 24 low-spin iron(II) ions. The magnetic iron(III) centres are ferromagnetically coupled, yielding the highest ground-state spin number (S=45) of any molecule reported to date.

One area of interest in the field of molecular magnetism is the development of high-spin molecules. Here, the authors report a cyanide-bridged nanocage consisting of 18 high-spin iron(III) ions ferromagnetically coupled through 24 low-spin iron(II) ions, with a ground state spin of S=45.