colored organic gas?

[sor...@aol.com]

I read an interesting comment is someone's description of
elemental bromine. The noted that it was rather unusual to
have a true colored gas, that most colored gas-like materials
were really dispersions of a colored solid in air and scattered light.

Now colored gases aren't really that uncommon:
NO2, Br2, Cl2, I2 (ok, a little about room temperature), F2 (pale),
CrO2Cl2, some of the interhalogens, a bunch of metal hexafluorides,
maybe O3. Everything on this list is a strong oxidizer (which in the
case of the metal compounds is related to the color - the absorbtion
is probably a charge transfer transition).

Are there any organic pi systems which are volatile enough, and
strongly absorbing enough (in the visible!) to be colored gases,
preferably at room temperature, but at least below the decomposition
temperature of the molecule? The closest that I've been able to find
seems to be azulene, though it boils at 242 C. Is there something
better?

Best wishes,
-Jeff

[Ian Gay]

sor...@aol.com wrote in
news:1147497823....@u72g2000cwu.googlegroups.com:

Perfluorothioacetone.

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[luc...@sbcglobal.net]

<sor...@aol.com> wrote in message
news:1147497823....@u72g2000cwu.googlegroups.com...

2,3-butanedione, also called diacetyl, b.p. 88C. Yellow liquid, comes over
as a rairly light yellow gas when you distill it.

Eric Lucas

[Uncle Al]

The smallest colored organic gas is diazomethane, CH2N2 - pale yellow.

2,3-butanedione is a deep yellow liquid that distills at ambient temp
as a green gas, bp 88 C.

You might look at gas phase nitrosomethane (tautomer of formaldehyde
oxime),

J. Chem. Ed. 59(10) 889 (1982)

Would it be colored or dimerized colorless?

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Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz3.pdf

[Chris Cooksey]

In article <4465F873...@hate.spam.net>, Uncle Al
<Uncl...@hate.spam.net> writes

Similarly, nitroso-t-butane which when distilled has the same color as
copper sulfate and the deep blue liquid solidifies to a white solid.
Quite spectacular !

--
Chris Cooksey

[sor...@aol.com]

Many thanks to all!

Best wishes,
-Jeff