CHEM 2311 Lecture Notes - Lecture 28: Benzene, Mnemonic, Hydrogenation
Document Summary
Chapter 14 aromatic compounds: benzene ~ c6h6, aliphatic ~ chemical behavior of compound was fatlike; didn"t dissolve in water, aromatic ~ compound has low hydrogen to carbon ratio and was fragrant. Benzene was the only structure that could gives only one derivative (c6h5x) Turns out that benzene was more stable than predicted. Relative energies of molecular orbitals in monocyclic conjugated hydrocarbons (mnemonic trick) Be able to draw the mos and any conjugated cyclic molecule. Cyclobutadiene is diradical which makes it highly unstable anti- aromatic: the structure pinches into rectangle to become more stable. Huckel"s rule: cyclic, planar arrays of conjugated p orbitals containing (4n+2) pi electrons are aromatic, n consists of 0,1,2,3,4 . 4 pi, 8 pi do not conform to 4n+2 rule for aromaticity. 8 pi electrons structure (cyclooctene) also puckers, creating a non-planar molecule it does this because its original structure is highly unstable. How to determine aromaticity checklist: 1.
