Complete optimization without geometry constraints and calculation of electronic properties of novel conic molecules such as C$_n$H$_n$Ge$_n$H$_n$ and C$_n$Ge$_n$H$_n$, with $n = 3−8$, was carried out with density functional theory using B3LYP and PBE1PBE functionals with 6-31$+$G(d, p) and cc-pVTZ basis sets. Calculations of formation energy showed stable and peculiar geometric and electronic properties. All carbon and germanium atoms for C$_n$H$_n$Ge$_n$H$_n$ compounds, which are sp$^3$-hybridized, were located in the same plane. This finding contradicts the notions of hybridization known to date. For these new molecular compounds, quantum descriptors such as electrochemical potential ($\mu$), chemical hardness ($\eta$), electrophilicity index ($\omega$), dipole moment, energy gap and the shape of the molecular orbital have been calculated in additionto nucleus independent chemical shifts, polarizability and harmonic oscillator model of aromaticity which are important tools for determining the aromaticity of the studied compounds. Thus, the aim of the work is, on the one hand, to propose new stable molecular structures formed of carbon and germanium atoms, and on the other hand, to challenge our understanding of hybridization and aromaticity notion.

COVID-19 pandemic started more than a year ago and has infected more than 115 million of people from ${\sim}$210 countries and >2.5 million of deaths worldwide being reported without any commercial and effective treatment or vaccine being yet released. However, recent studies on nanomaterials such as fullerenes, carbon nanotubes and graphene showed that they possess anti-inflammatory, antiviral, anti-oxidant and anti-HIV properties. Herein, the interactions which established between the fullerenes $C_m$ (m = 48, 60, 70, 80, 84 and 86) and the spike protein (SP) of SARS-CoV-2 and the human ACE2 receptor have been investigated based on the density functional theory (DFT) method with the CAM-B3LYP functional and the 6-31G* basis. The results of this study show that C48 exhibited as potential inhibitor of SARS-CoV-2. Because of the presence of heteroatoms on the surface of fullerenes which systematically reduce energy gaps, which in turn increase their reactivities. The oxygen adsorbed by fullerenes increases the number of non-covalent contacts and involves a large number of hydrogen bonds, while decreasing the binding energies. Thus, the hACE2-SP-4O$_2$@C60 complex is strongly recommended for inhibiting SARS-CoV-2 in the final phase of contamination.