From Small Metal Clusters to Molecular Nanoarchitectures with a Core-Shell Structure: The Synthesis, Redox Fingerprint, Theoretical Analysis, and Solid-State Structure of [Co(38)As(12)(CO)(50)](4)

The cluster [Co(38)As(12)(CO)(50)](4-) was obtained by pyrolysis of [Co(6)As(CO)(16)](-). The metal cage features a closed-packed core inside a Co/As shell that progressively deforms from a cubic face-centered symmetry. The redox and acid-base reactivities were determined by cyclic voltammetry and spectrophotometric titrations. The calculated electron density revealed the shell-constrained distribution of the atomic charges, induced by the presence of arsenic.