Ligand stabilization of manganocene dianions – in defiance of the 18-electron rule

Abstract

Di-anions of manganocene derivatives complexes, in spite of being a 19-electron system, are found to be more stable than their mono-anions. This defiance of the 18-electron rule is linked to the geometrical distortion of the di-anion, akin to the Jahn-Teller-like mechanism.

Metal Deficiency Tailored by the 18-Electron Rule Stabilizes Metal-Based Inorganic Compounds

“…The 18-electron (18-e – ) rule or effective atomic number (EAN) or effective electron count (EEC) or valence electron count (VEC) rule states that thermodynamically stable transition-metal compounds contain 18 valence electrons around each metal center contributed by ns, np, and (n-1)­d-electrons of the metal and the electrons supplied by the metal-bound ligands. It is one of the critical criteria for understanding the stability and chemical structure of various materials, metal complexes, and organometallics. − Satisfaction of the VEC rule and considering the atomic size of the constituent elements determines the stability of the final crystal structure . However, how these changes (for example, in, atomic radii, oxidation state) work with the 18-e – rule in the intermetallic system has not been discussed in depth, calling for a detailed study in this subject.…”

Zintl Lewis Superacids: Al(Ge9L3)3 (L = H, CH3, CHO, CN)

“…Nowadays, the idea about Zintl ions is not confined to group 13−15 elements. A recent study by Jena et al 14 even predicted stable Zintl like ions composed of all transition metals. The stability of such Zintl like ions can be analyzed by the 18-electron rule.…”