Tuesday, March 20, 2007

Alkenes

Yesterday was a day to start talking about alkenes. We spent most of the time discussing the physical chemistry of the C=C bond -- how it consists of an end-to-end bond and a side-to-side pi bond. I used the example of a pair of forearms and showed how they had to be parallel in order for the bond to exist; as a result it is nearly impossible to rotate around a C=C bond. We also saw the basis for Zaitsev's rule. Essentially, it is hyperconjugation that is responsible for the increased stability of more highly substituted alkenes. At the end, we saw a foreshadowing of the chemistry that we will discuss, the ability of the alkene to act as a Lewis base.

Modeling #7 has been posted; molecule slips will be available tomorrow.

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