Weak interactions such as halogen bonding interactions and other sigma-hole type interactions are often not purely due to electrostatics or charge transfer. The insistence in one direction or the other often proves to be somewhat misguided. We find some evidence that strong sigma-hole interactions can be separated by small, large, and no barrier whatsoever from strong covalent interactions, and where the barriers to bond formation disappears it appears to be sure in fact to how strong the ‘weak’ interactions actually are. We examine the role of such interactions for M-H activation, where M = C, Si, and Ge. We show that while C-H and Ge-H bond activation by hypovalent species can have formidable barriers, the reactions is often barrierless in the case of silicon. We probe the reasons for this phenomenon and identify sigma hole interactions as prime drivers for the barrierless reactions of Si and we account for the observation that in bond activation reactions germanium is likely to behave much more like carbon than silicon. We consider briefly other places where sigma-hole interactions to group 14 central atoms have significant consequence or have been identified experimentally.<br/> <br/> <br/>

Potential roles for sigma hole interactions in M-H bond activation and elsewhere

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.