Hello to all:
I was studying the chapter on Aromatics in Organic Chemistry and
came up with some questions and was wondering if I could get your
opinions on the subject.
1) My textboox cites ciclooctatetraene dianion as an example of an
aromatic ion (a dianion in this case). Surely it follows Huckel's rule
with 10e-; however, using Frost's circle I see that while all e- are
paired, the last four are in non-bonding orbitals. Is this really a
particularly stable arrangement?
2) It seems to me that a more stable arrangement would be the
cyclooctatetraene dication with 6e- and that would place all e- in
bonding orbitals and none on non-bonding or antibonding orbitals. The
dianion seems a more common example (looked in several books) that the
dication and I am wondering why. Is it just that authors have made a
poor choice of example or is it that for some reason I cannot see the
anion is indeed a better example?
3) Tropylium bromide is cited as an example of an aromtic cation with
6e-. The book says it is a stable ionic compound. I am wondering about
the existance of other "aromatic salts". Do things like sodium
pentadienide, or the salt of the cyclooctatetraene dianion or cation
Thanks in advance for your comments