Neutral all metal aromatic half-sandwich complexes between alkaline earth and transition metals: an ab initio exploration

Abstract

Sandwich complexes nd their interests among the chemists after the breakthrough discovery of ferrocene. Since then, a number of sandwich and half sandwich complexes were predicted and synthesized. Herein, we have theoretically proposed a series of half-sandwich complexes involving a neutral Be 3 ring and transition metal. Quantum chemical calculations have shown that the proposed complexes are quite stable involving high bond dissociation energies. The thermodynamics of their formation is also favorable. The Be 3 ring in all cases posses dual aromaticity which has been ascertained based on magnetic as well as topological feature of electron density.

Viability of half‐sandwich complex of heavier group‐14 elements (SiPb) with neutral Be3ring and its potential application asH2storage material

“…We then investigated the aromatic character of the proposed half‐sandwich complexes by doing nucleus independent chemical shift (NICS) calculations. As Be 3 ring is found to be anti‐aromatic in nature with in plane NICS value of 20 ppm [17], it is expected that after complexation with Y, we should observe induced aromatic behavior. Frontier Kohn‐Sham orbitals (Figure 4) indicates the presence of five molecular orbitals having 10 valence electrons encompassing a tetrahedral cage like structure.…”

“…Although the library of such complexes containing transition metals is rich, but half‐sandwich complexes of main group elements are limited in the literature. Recently our group predicted the half‐sandwich behavior of neutral Be 3 ring with some transition metals (Fe, Ru, Os, Zn, Cd, and Hg) [17]. The motive was to incorporate a transition metal two electron donor to neutral Be 3 ring to make the overall system aromatic.…”