Dolbier HW Solutions 260

Dolbier HW Solutions 260 - to generate a more stable one:...

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254 ARENES AND AROMATICITY The measured heat of hydrogenation is Therefore Resonance energy 5 330 kJ/mol (predicted for no delocalization) 2 305 kJ/mol (observed) 5 25 kJ/mol (5.9 kcal/mol) The value given in the text for the resonance energy of benzene (152 kJ/mol) is six times larger than this. 1,3,5-Cycloheptatriene is not aromatic. 11.3 ( b ) The parent compound is styrene, C 6 H 5 CH ? CH 2 . The desired compound has a chlorine in the meta position. ( c ) The parent compound is aniline, C 6 H 5 NH 2 . p -Nitroaniline is therefore 11.4 The most stable resonance form is the one that has the greatest number of rings that correspond to Kekul é formulations of benzene. For chrysene, electrons are moved in pairs from the structure given
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Unformatted text preview: to generate a more stable one: 11.5 Birch reductions of monosubstituted arenes yield 1,4-cyclohexadiene derivatives in which the alkyl group is a substituent on the double bond. With p-xylene, both methyl groups are double-bond sub-stituents in the product. H 3 C CH 3 p-Xylene H 3 C CH 3 1,4-Dimethyl-1,4-cyclohexadiene Na, NH 3 CH 3 CH 2 OH More stable: four rings have benzene bonding pattern. Less stable: two rings have benzene bonding pattern. NH 2 NO 2 p-Nitroaniline m-Chlorostyrene CH Cl CH 2 1 3H 2 D H 8 5 2 305 kJ ( 2 73.0 kcal) 1,3,5-Cycloheptatriene Cycloheptane...
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This note was uploaded on 09/26/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.

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