H h transtrans i som r e planar structuretoo crowde

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Unformatted text preview: 11 kcal m -1 r ol [10]Annulene: Aromatic? H H trans,trans I som r e Planar structuretoo crowde by theinside d Planar hydroge . Othe isom rs suffe bond anglestrain: ns r e r bond hydroge Othe Unde e ctrocyclic ring closure ! rgo le s H H 154º H hυ con H ∆, ∆, 25 °C bot h 10 ° C H H dis all-cis I som r e H H S olution to this proble : Bridge m d annule s: 1,6ne annule Me thano[10]annule . ne S table be s m likebe ne ; have uch nze [18]Annulene [18]Annulene Franz S im r Franz ondhe e 1926-1981 The first unstrained The aromatic annulene aromatic [16]Annulene: Antiaromatic Antiaromatic TheAnnule s ne The Cyclobut adiene: planar , ant iar omat ic Benz ene: planar , ar omat ic Cyclooct at et r aene: nonplanar = nonar omat ic [ 1 0 ] Annulene: nonplanar = nonar omat ic [ 1 2 ] Annulene: planar = ant iar omat ic [ 1 4 ] Annulene: planar = ar omat ic [ 1 6 ] Annulene: planar = ant iar omat ic [ 1 8 ] Annulene: planar = ar omat ic 1 , 3 - Cyclopent adiene: noncyclically delocaliz ed = nonar omat ic 1 , 4 - Cyclohex aadiene: noncyclically delocaliz ed = nonar omat ic Charged Annulenes Charged (prope = 40) ne Se ix But, thecyclope ntadie cation is antiarom nyl cation atic, ve unstable m worsethan allyl ry ,...
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This note was uploaded on 09/06/2010 for the course CHEM 10894 taught by Professor Pederson during the Fall '10 term at University of California, Berkeley.

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