An icosahedral Ta12(2+) cluster with spherical aromaticity.

A high-stability icosahedral cluster (Ta12(2+)) with spherical aromaticity was found within a DFT framework. The spherical aromaticity of the icosahedral Ta12(2+) cluster was confirmed by a high symmetry, a short bond length, a high vibrational frequency, a large HOMO-LUMO gap and negative NICS(0) values. The icosahedral Ta12(2+) cluster is the first example of a bare metal cluster with a total of 58 valence electrons. The electron density topological analyses (QTAIM and ELF) indicate that three-center shared interactions exist in the icosahedral structure. The IR and absorption spectra were theoretically simulated as a convenient way to confirm the existence of the icosahedral structure in further experiments.