Theoretical study on the interconversion of silabenzenes and their monocyclic non-aromatic isomers via the [1,3]-substituent shift: Interplay of aromaticity and Bent's rule

•Isomerization of silabenzenes to the non-aromatic isomers was examined thoroughly.•The contribution from aromaticity can be evaluated quantitatively in this process.•Bent's rule plays an important role in such an isomerization.•An interconversion of silabenzenes and the non-aromatic isomers can be achieved.•Our findings could be a useful guide to the synthesis of silabenzenes.

Density functional theory (DFT) calculations were performed to examine the substituent effects on the interconversion of silabenzenes and their monocyclic non-aromatic isomers. A previous study suggested that aromaticity is the driving force for this process. Interestingly, our systematic calculations reveal that the contribution from aromaticity can be evaluated quantitatively (ca. 30 kcal mol−1). Thus it is the interplay of aromaticity and Bent's rule that determines their relative stabilities. In addition, strong correlations of reaction energies as well as reaction barriers have been identified against the s character of Si in the Si-X bonds, providing an important guide to the synthesis of silabenzenes.

Graphical abstractDFT calculations reveal that it is the interplay of aromaticity and Bent's rule that determines the relative stabilities between silabenzenes and their non-aromatic isomers, providing an important guide to the synthesis of silabenzenes.Figure optionsDownload full-size imageDownload as PowerPoint slide