Mn6

Mn6 is a designation used in inorganic and organometallic chemistry to refer to a family of compounds and clusters that contain six manganese atoms. These clusters may exist as neutral species or as charged ions and are stabilized by a variety of ligands, including carbon monoxide, halides, phosphines, cyclopentadienyl, oxo bridges, or μ-hydride bridges. The six manganese centers share metal–metal bonding, giving cores that can adopt several geometries, including octahedral-like arrangements or wheel- or prism-type topologies, depending on the ligand environment.

The oxidation states of manganese within Mn6 clusters depend on the ligands and overall charge; individual Mn centers are typically in positive oxidation states in oxidized clusters, but mixed-valent forms are also common. Structural and electronic diversity arises from differences in ligand sets and connectivity, which influence properties such as magnetism and redox behavior.

Synthesis and characterization: Mn6 clusters are typically prepared by assembling manganese sources under reducing conditions in the presence of stabilizing ligands, sometimes via assembly from smaller Mn-containing fragments. Structural characterization is normally accomplished by X-ray crystallography, with electronic and magnetic properties probed by UV–visible spectroscopy, electron paramagnetic resonance, and magnetometry to assess spin states and coupling between centers.

Properties and applications: Magnetic properties of Mn6 clusters often reflect high-spin ground states due to unpaired electrons on multiple manganese centers. The clusters are studied for insights into metal–metal bonding in first-row transition metals and have been explored as catalysts for organic transformations and as precursors to magnetic materials or nanostructures. They also serve as model systems in fundamental studies of cluster bonding.

See also: manganese cluster compounds; transition metal carbonyl clusters; single-molecule magnets.