(c)Cycloundecapentaenyl cation is aromatic.It includes a completely conjugated psystemwhich contains 10 pelectrons (10 equals 4n12 where n52).(d)Cycloundecapentadienide anion is not aromatic.It contains 12 pelectrons and thus does notsatisfy the (4n12) rule.11.45(a)The more stable dipolar resonance structure is A because it has an aromatic cyclopentadienideanion bonded to an aromatic cyclopropenyl cation. In structure B neither ring is aromatic.(b)Structure D can be stabilized by resonance involving the dipolar form.Comparable stabilization is not possible in structure C because neither a cyclopropenyl sys-tem nor a cycloheptatrienyl system is aromatic in its anionic form. Both are aromatic ascations.11.46(a)This molecule, called oxepin,is not aromatic.The three double bonds each contribute 2 pelectrons, and an oxygen atom contributes 2 pelectrons to the conjugated system, giving a
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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.