Toluene to Tropylium ions?

I have heard of Toluene being converted to small amounts of the Tropylium ion in gas phase. (I think it might have had to do with interaction with light (?) ) So it begs the question of if Benzyl Chloride might be converted to Tropylium Chloride.
Naturally, the yields would not be spectacular, but it could be an interesting source of the Tropylium ion.

http://pubs.acs.org/cgi-bin/abstract.cgi/jpcafh/2004/108/i45...
Toluene can rearrange into both benzilium ion and tropylium ion through photodissociation.

http://216.239.51.104/search?q=cache:VD2OtVYXx-YJ:article.pu...
"On this basis the C7H7+ ions were identified as bz+ and tr+ respectively ... It is concluded that a rearrangement from benzyl to tropylium cations and vice versa does not occur until at least 300*C..."
(This was actually quite an interesting article )


http://www.nature.com/nature/journal/v184/n4701/abs/1841796a...
"IONIZATION by electron impact of toluene1,2 and some other compounds containing the benzyl group3 leads to the formation of tropylium ions"

There are quite a few interesting things dealing with this. A simple google search yields many interesting results. Try "toluene tropylium" if you're interested.

EDIT

It has also occurred to me that this could be used to produce garage cycloheptatriene. Not sure how useful it would be but thats not important.

[Edited on 28-6-2007 by halogen]

I think you misunderstood. It is not toluene that equilibrates with the tropylium ion, but the benzylic cation (PhCH₂⁺. This happens in the gas phase where the cation can be "free" (like in the mass spectrograph). Therefore, it is obviously not possible to use this property of the benzylic cation as preparative method for preparing tropylium salts. Though in the condensed phase the benzylic cation forms easily from benzyl halides, alcohols and similar with the aid of very strong acids, it is still impossible to prepare a stable solution of benzylic cation salts since it readily reacts with itself.

"I think you misunderstood. It is not toluene that equilibrates with the tropylium ion, but the benzylic cation (PhCH2+). "

Ah, my mistake, I worded it poorly.
But my hypothesis about about using benzyl chloride seems more plausible.