Substitution effects on novel bicyclo[2.2.1]hepta-7-silylenes by DFT.

Abstract

Substitution effects on stability (ΔΕs-t) of novel singlet and triplet forms of bicyclo[2.2.1]hepta-7-silylenes are compared and contrasted, at B3LYP/6-311++G** level of theory. All species appear as ground state minima on their energy surface, for showing no negative force constant. Singlets (1s-24s) are ground state and more stable than their corresponding triplets (1t-24t). The most stable scrutinized silylenes appear to be 2,3-disilabicyclo[2.2.1]hepta-7-silylene (9) for showing the highest value of ΔEs-t. This stability can be related to our imposed topology and β-silicon effect. The band gaps (ΔΕHOMO-LUMO) show the same trend as ΔEs-t and the lowest unoccupied molecular orbital energies. Also, the electrophilicity appears inverse correlation with our results of ΔΕs-t. The purpose of the present work was to assess the influence of 1 to 6 silicon substitutions on the stability, band gaps, nucleophilicity, electrophilicity, and proton affinity. Finally, our investigation introduces novel silylenes with possible applications in chemistry such as semiconductors, cumulated multidentate ligands, etc. Synopsis Substitution effects on stability (ΔΕs-t) of novel singlet (s) and triplet (t) forms of bicyclo[2.2.1]hepta-7-silylenes are compared and contrasted, at B3LYP/6-311++G** level of theory. All species appear as ground state minima on their energy surface, for showing no negative force constant. Singlets (1s-24s) are ground state and more stable than their corresponding triplets (1t-24t). The most stable scrutinized silylenes appear to be 2,3-disilabicyclo[2.2.1]hepta-7-silylene (9) for showing the highest value of ΔEs-t. This stability can be related to our imposed topology and β-silicon effect. The purpose of the present work was to assess the influence of 1 to 6 silicon substitutions on stability (ΔΕs-t), band gaps (ΔΕHOMO-LUMO), nucleophilicity (N), electrophilicity (ω), and proton affinity (ΔΕPA). Finally, this new generation has the intrinsic potential to form accumulated multidentate ligands.