CPSC 382Organic Chem Ag Biol ProcTopic #4 - Aromatic Compounds and Conjugated Bond Systems1. Definition of the term “aromatic”2. Structure and properties of benzenea. unusual reactivity unlike alkenesb. Kekule’s model and resonance structuresc. bond lengths in the ring structured. resonance energy (“resonance stabilization energy”)e. molecular orbital model for benzene3. Concept of “aromaticity”4. Nomenclature for benzene compounds5. Electrophilic substitution reactions of benzene compoundsa. general reactionb. effects of ring substitutents on reaction ratec. effects of ring substitutents of location of subsequent substitution reaction-- “ortho, para-directing” and “meta-directing” substitutents6. Polycyclic aromatic compounds7. Conjugated bond systems and the “mesomeric effect”8. Role of aromaticity in the function of chlorophyll in photosynthesisStructure of benzene:Concept of “Resonance Energy”:Molecular orbital description of benzene structure:Concept of “aromaticity”:Nomenclature for benzene aromatic compounds:Electrophilic substitution reactions:Polycyclic compounds (polynuclear aromatic compounds): Conjugated bond systems and the “mesomeric effect”:Chlorophyll, photosynthesis and role of