Organo−Zintl-based superatoms: [Ge9(CHO)3] and [Ge9(CHO)]

[Display omitted] •Organo-Zintl cluster derived from group 14 Zintl ion Ge94− and Ge92− with CHO as ligand.•Organo-Zintl Cluster [Ge9(CHO)3], [Ge9(CHO)] are mimicking the properties of halogens.•Stability of these clusters have been analysed in terms of Jellium shell closer model and Wade-Mingos rule.•The molecular orbitals of these organo-Zintl clusters are similar to the chorine and iodine elements.•These clusters are also mimicking the properties of Al13 cluster, a well-known superatom. A systematic study, based on density functional theory and different hybrid functionals for exchange-correlation potential, shows that the electron affinities of organo-zintl clusters [Ge9(R)n] [R=CHO; n=1, 3] are close to that of chlorine (3.6eV) and iodine (3.0eV). A detailed study of the molecular orbitals of these complexes, when compared to those of Al13−, Cl− and I−, confirm that they behave as superatoms, mimicking the chemistry of halogens. This study expands the scope of superatoms by including a new class of pseudo-halogens based on ligated organo-Zintl ions.