CHEM 1061 Lecture Notes - Lecture 23: Trigonometry, Alkene, Phenyl Group
Document Summary
Have at least one double carbon bond. Double bond is the most reactant in the compound. Alkenes with less than three carbons: location of the double bond is indicated by the lowest numbered carbon involved. Cis/trans isomerism: caused by the restricted rotation around the double bond, cis-2-butene (zusammen) o o. When a side chain is present, start counting at the double bond. 1 sigma bond between the sp orbitals on the triple bonded carbons. 2 pi bonds between the 2 sp orbitals on each carbon o. Pi bonds (weaker than the c-c sigma bonds) are broken and new sigma bonds are made to the atoms being added. Special class of unsaturated hydrocarbons that are resonance stabilized. C6h6: simplest aromatic hydrocarbon, characterized by planar ring structure (all bond angles are 120) Resonance structures are used to account for known equivalence of all c-c bonds: delocalization of pi electrons indicated by an inner circle.
