Novel silanetellones: Structures, ionization potentials, electron affinities, singlet–triplet gaps and Kohn–Sham HOMO–LUMO gaps of the X2SiTe and XYSiTe (X, Y = H, F, Cl, Br, I and CN) molecules

A systematic investigation of the X2SiTe and XYSiTe (X, Y = H, F, Cl, Br, I and CN) species is carried out using the second order Møller–Plesset Perturbation theory (MP2) and the density functional theory (DFT). The structures and energetics such as the ionization potentials (IPad and IPad(ZPVE)), the four different forms of neutral–anion separations (EAad, EAad(ZPVE), VEA and VDE), the singlet–triplet gaps, the Kohn–Sham HOMO–LUMO gaps are reported. The electronegativity (χ) reactivity descriptor for the halogens (F, Cl, Br and I) is used as a tool to assess the interrelated properties of these silanetellone derivatives. Besides, the nucleophilicity (N) and global electrophilicity (ω) indices are also predicted. The computations performed using the B3LYP functional, predict IPad(ZPVE) values ranging from 8.33 eV (H2SiTe) to 9.23 eV (NC)2SiTe), the EAad(ZPVE) ranges from 1.60 eV (H2SiTe) to 3.61 eV (NC)2SiTe), the singlet–triplet gaps range from 0.57 eV (H2SiTe) to 1.15 eV (F(NC)SiTe). The mentioned silanetellones are predicted to be viable since the lowest vibrational frequency is >100 cm−1 in most of the cases. The results obtained are critically analyzed, discussed and compared with the literature of X2SiZ and XYCTe (X, Y = H, F, Cl, Br, I and CN and Z = O, S and Se) systems. Since experimental data are still lacking for silanetellones, the findings of this work would add to the literature and assist experimentalists to further explore and rationalize some reactions pertaining to these novel species.