COMP 411 |
| We have shown that the stable pentavalent transition complex [Nu-P(O)R2-L]– occurring in SN2@P reaction systems may become embedded in between pre- and post-transition states (and, eventually, even turn into a labile transition state) if the steric bulk of the substituents R exceeds a certain threshold. Here, we explore the PES of SN2@P reaction systems in further detail. Our investigations reveal a rich cluster chemistry of complex and competing multistep processes. We observe, in certain instances, the occurrence of additional structures on the PES of the pentavalent intermediate that originates from stepwise "Walden flipping" of the substituents (see figure). Furthermore, competing side reactions may take place both from the pre-reaction complex as well from reactive intermediates. The regular back-side SN2@P reaction has to compete, among others, with proton transfer and front-side SN2@P reactions in which the substituents R play the role of leaving group.
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Quantum Chemistry
1:30 PM-4:15 PM, Wednesday, August 22, 2007 BCEC -- 162A, Oral
Division of Computers in Chemistry |
