Abstract
We have quantum chemically investigated the nature and stability of C-C and Si-Si bonds in R3A-AR3 (A = C, Si; R3 = H3, Me3, Me2Ph, MePh2, Ph3, t-Bu3) using density functional theory (DFT). Systematic increase of steric bulk of the substituents R has opposite effects on C-C and Si-Si bonds: the former becomes weaker whereas the latter becomes stronger. Only upon going further, from R = Ph to the bulkiest R = t-Bu, the R3Si-SiR3 bond begins to weaken. Our bonding analyses show how different behavior upon increasing the steric bulk of the substituents stems from the interplay of (Pauli) repulsive and (dispersion) attractive steric mechanisms. Extension of our analyses to other model systems shows that C-Si bonds display behavior that is in between that of C-C and Si-Si bonds. Further increasing the size of the group-14 atoms from C-C and Si-Si to Ge-Ge, Sn-Sn and Pb-Pb leads to a further decrease in the sensitivity of the bond strength with respect to the substituents' bulkiness. Our findings can be used as design principles for tuning A-A and A-A′ bond strengths.
Original language | English |
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Pages (from-to) | 1648-1656 |
Number of pages | 9 |
Journal | Chemical Science |
Volume | 15 |
Issue number | 5 |
Early online date | 16 Jan 2024 |
DOIs | |
Publication status | Published - 7 Feb 2024 |
Bibliographical note
Publisher Copyright:© 2024 The Royal Society of Chemistry.
Funding
This work is part of the Advanced Research Center for Chemical Building Blocks (ARC CBBC; grant 2018.019.B), which is co-founded and co-financed by the Dutch Research Council (NWO) and the Netherlands Ministry of Economic Affairs and Climate Policy. This work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative. Furthermore, we thank Dr Lucas de Azevedo Santos and Dr Pascal Vermeeren for helpful discussions.
Funders | Funder number |
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Advanced Research Center for Chemical Building Blocks | 2018.019 |
Netherlands Ministry of Economic Affairs and Climate Policy | |
SURF Cooperative | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek |