ORGN 393 |
| Why is silicon hypervalent and carbon not? Or, why is [Cl-CH3-Cl]– labile, with a tendency to localize one of its axial C–Cl bonds and to largely break the other one, while the isostructural and isoelectronic [Cl-SiH3-Cl]– forms a stable pentavalent species, with a delocalized structure featuring two equivalent Si–Cl bonds? Various hypotheses have been developed over the years focusing on electronic but also on steric factors. Here, we present the so-called ball-in-a-box model (see illustration) which tackles hypervalence from a new perspective. The ball-in-a-box model reveals the key role of steric factors and provides a simple way of understanding the above phenomena.
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High Energy Species
8:00 AM-11:40 AM, Tuesday, August 21, 2007 BCEC -- 254 A/B, Oral
Division of Organic Chemistry |
