BMB 208 Lecture Notes - Lecture 7: Cyclooctatetraene, Phenol, Conjugate Acid
Document Summary
*notes not on exam 1 and exam covers chapters 10 and 11. Huckel"s rule: the 4n + 2pi electron rule, all conjugated ring systems are not aromatic like benzene, benzene: Closed shell of pi electrons when planar: cyclooctatetraene. Does not have closed shell of pi electrons when nonplanar: rule: conjugated monocyclic ring systems with 4n + 2(n=0,1,2,3 , huckle numbers: 2,6,10,14, . Pka"s: weak acids have large pka values, the pka is dependent on the size and nature of the r group, strong acids have low or negative pka values. Amides: amides are weak bases, in the unprotonated (basic) amine the electron density resides on the amino nitrogen and is localized, in the amide, the electron pair on the nitrogen is delocalized to the oxygen through resonance. This also puts a partial positive charge on the nitrogen which would tend to lower proton association.