Comments on: Buckyballs

Question: Buckyballs

brownpau — Tue, 30 Mar 2004 11:23:44 -0800

What does buckminsterfullerene (a.k.a. "buckyballs") look like in macro? We see lots and lots of computer-generated images of the molecule itself, but how about an aggregation of the stuff in a test tube? Is it a black goo or something?

By: vacapinta

vacapinta — Tue, 30 Mar 2004 11:37:56 -0800

buckyballs are a form of carbon (C60)

From the site Chemical of the week:

The amounts of buckminsterfullerene ("buckyballs," for short) prepared by laser were extremely small. The evidence for the structure would remain sketchy until C60 could be prepared in larger quantities. Such a preparation was discovered in 1990. In this method, a water-cooled cylinder contains a sharp graphite rod touching a graphite disk. The cylinder is evacuated to a pressure of 1 × 105 torr, and a current of 100 to 200 ampere is passed between the rod and the disk. This produces a soot that deposits on the walls of the cylinder. The soot is washed with toluene, producing a red-brown solution. When this solution is evaporated, it leaves a residue with a mass of about 10% of the original soot and containing more than 85% C60. With this method, about 1 gram of C60 can be produced in a day

By: vacapinta

vacapinta — Tue, 30 Mar 2004 11:43:43 -0800

Also,

After 20 - 30 min the magenta colour of pure C60 will appear and should continue for a further 20 min or so.

via this page.

By: bonehead

bonehead — Tue, 30 Mar 2004 13:30:02 -0800

There's a nice picture of various fullerenes in solution (toluene, I think) here

Fullerenes are strongly coloured because they have a large delocalized pi-electron^#*!@$ cloud which gives them lots of states in the UV/Visable light frequencies. The electron cloud shape changes with the geometry of the fullerene, so the colours shift as the numbers of carbons increase. Mix a whole bunch of different types together and you get strong absorbance across the whole visible spectrum. A bunch of mixed fullerenes are deep black.

Fullerenes are a class of PAHs (sort of) and most commonly found in burn products like soot.

^#*!@$Dammit! Can't do greek entities!

By: five fresh fish

five fresh fish — Tue, 30 Mar 2004 17:51:01 -0800

You mean the π entity?