applications - and analogies Resonance Analogy Using Cartoon Characters Ronald Starkey Jn vers ly of W~sconsn-Green Bay Green Bay. WI 54311
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Several eood analoeies have been out forth in a n attemut to clarify the concept of resonance. In many cases the originator of these analoeies is unknown. Most oreanic chemists are familiar with the dragon-unicorn model for describing a rhinoceros, and the Don Juan-Don Quixote model to describe a real individual. An a n a l o-. w I have found useful i n oreanic chemistrv classes involves cartoon characters t h a t represent contributors to a resonance hvbrid. For examole...YOU miaht need to describe your nephew Bob to someone who Kas never seen him. Aphotograph of Bob, that would certainly be useful to help depict him, is not available. You might attempt to describe Bob in terms of two fictional characters, Charlie Brown and Dennis the Menace. Bob is like Charlie, but not exactly; because h e also h a s characteristics of Dennis. Your nephew Bob is a real person who is neither Charlie nor Dennis, but he has characteristics of these two fictional characters. Although you can produce
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edited by RONDELORENZO Middle Georgia College Cochran. GA31014
drawings of both Charlie and Dennis, neither really exists. The drawings help in obtaining a composite view of the real person Bob, who has not been seen.In drawina Charlie and Dennis. all the rules for drawine real people a r e followed; rules s;ch as, a head with two eyes and a nose, two arms and legs, etc. J u s t because you can draw a reasonable looking person does not necessarily mean that the individual reallyexists. Conversely, just because vou cannot draw a sinele eood uicture of Bob vou cannot conclude that he does not exist. I n this situation i t required drawings of two fictional characters to get a fairly accurate descriution of vour neohew Bob. Despite the use of two drawings to characterize Bob, this does not mean Bob is sometimes Charlie and a t other times Dennis. He is always Bob, but in this case i t is not possible to portray him accurately with one drawing. The extension to a resonance hybrid model of benzene is obvious. Benzene is a real molecule. We do not have a single good picture of it, but we can draw two structures of non-real molecules that allow us to help describe the structure of benzene. Benzene is neither of the s t n ~ c t u r e swe draw a s resonance contributors, but i t is a composite of these two structures.
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The Charlie Brown-Dennis the Menace resonance analogy."Charlie Brown": 0 1950 United Features Syndicate,Inc. "Dennisthe MenaceiW used by permission of hank Ketchem. 0 North American Syndicate.
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Journal of Chemical Education
