Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Evidence of hollow golden cages

Since you guys are so keen on posting physics articles, I figured I'd give the chemists something to talk about.

http://www.pnas.org/cgi/content/abstract/103/22/8326

This is new to me and a great find: Thanks.

The reason there isn't much chemistry here is that the uneducated all believe they understand physics.

But start talking about Friedels-Crafts alkylations and they'll quickly head for the closet. What chemistry has made it here has been things such as the discovery of bucky balls around stars in our galaxy.

Physics is rich with indeterminate propositions (crackpots) because it values theory over reduction to practice. Chemistry is primarily experimental. If it doesn't happen it isn't there. Ya gotta know real world stuff.

"they have found evidence of the first free-standing hollow cage structure composed of clusters of pure metal atoms"

"Found evidence?" Is that like a crystal structure or is that like a logical argument? Crystal structures carry weight. The very large atomic number of gold should make a structure determination a snap. Did it?

for my part, chemistry is too much about equations and i dont talk equations very well.

They used photoelectron spectroscopy. They slam the sample with UV or X-Ray light in a vacuum and measure the kinetic energy of the ejected electrons. This reveals metal oxidation state and bonding environment.

dehammer wrote:
"for my part, chemistry is too much about equations and i dont talk equations very well."

Yeah. Sort of like astronomy, math, meteorology, physics ... the stuff we call the sciences.

http://www.mazepath.com/uncleal/xheli.png
http://www.mazepath.com/uncleal/benzil.png
http://www.mazepath.com/uncleal/cn3.png
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Do you see any equations in there, boy? Organic chemistry is about real world reduction to practice not theoretical calculation. Organikers do it. If theory doesn't like the observation theory can change until it does like the observation.
No hard evidence. Conjecture. Damned near anything can be made in vacuum if you look fast enough at a low enough temperature and can detect single cases. Reality sits in a sample vial.

DA Morgan said: "The reason there isn't much chemistry here is that the uneducated all believe they understand physics."

This is an interesting remark. In my opinion every physicist, at some point in their career, should make a serious effort to prove to him/herself that atoms really exist. Some might be surprised to find out how fundamental and important chemistry really is.

Much of modern physics is about atomic and subatomic "things." From a philosophical point of view it would be good to be talking about something real! This is especially true if one wishes to understand, say, Quantum Chemistry or Chemical Kinetics.

Like Uncle Al says: "Ya gotta know real world stuff." I couldn't put it better!


Dr. R.

ive yet to see meteorlogist use equations to descipe the tempature or the amount of cloud cover. all ive seen is partially sunny, or wind at x speed, or x amount of rainfall in a certain area. those are not equations, they are simple numbers.

astronomers used coordiantes, not equations for the location of a star. they do use an equation for an orbit, but thats about all i know of that is actually an equation. Physics (unless you get into the higher levels, well beyound this forum) use names for the most part. ONLY a showoff uses forumlas in a sentence a lot. simple forumlas are one thing, but serious discuss of chemsitry requires high levels forumula in the discussion. low level discussion of formulas i can handle, but the higher ones lose me quickly.

discuss lasers and i can go for hours, but discuss the various type of connections between atoms like ive heard chemistry students do and i get lost very quickly.

I'm not convinced that justifies a response, but I can't resist.

"ive yet to see meteorlogist use equations to descipe the tempature or the amount of cloud cover."

Jeez man, please proof read. Does someone really need to explain to you that the average American is not a scientist and has no desire to watch someone derive formulas on television. Or, that most meterologists get absolutely no time on TV. Even H.S. physics uses math. You would have been better off making your argument by pointing out that behavioral scientists don't use math. But, instead you chose just to make dr_rocket seem wrong. It's clear to everyone here but you, that you are wrong. You have absolutely no idea what you are talking about on this one. Please drop this debate.

what i was trying to say is that like the average american your pointing at, I am not good at the formulas and i watch meterologist on tv all the time. as I pointed out, I can handle lower lvl formulas, but not the higher lvl ones that are used to discuss chemistry. Yes they do use formulas in high school physics, how else could they teach those formulas to students of physics, but those are usually lower lvl formulas which are usually used in test then forgotten. I know of several people who talk about chemistry and cant follow a quarter of their talk. Talk about physics and you get terms like black hole, and big bang, which you can follow even without a physics degree.

talk about chemistry and you get things like 'Quantum Chemistry or Chemical Kinetics' or things like c12h6o3+o?=?????. thing like that and im lost. a lot of people are. People dont like to feel dumb. lot of people feel dumb when you start talking formulas. that is why i said that i personally dont talk chemistry. Because it makes me feel dumb.

i made that comment because of:

i have not the faintest idea what a "Friedels-Crafts alkylations" is and have no interest in making myself look dumb. I know what bucky balls are (in basic terms) and know what dark matter is (in layman's terms) and have a basic understanding of black holes, big bang and things like that. those things i can discuss without feeling like an idiot. a lot of others are in the same boat as me.

for one thing there is no need to show your arragance by calling me "boy". im 47 years old, a disabled vet, and i have a college degree. it just has nothing to do with chemistry.

for another thing, your links prove what i was trying to say. thanks for the support.

Uncle Al,

"No hard evidence. Conjecture. Damned near anything can be made in vacuum if you look fast enough at a low enough temperature and can detect single cases. Reality sits in a sample vial."

Nothing suggests that these samples were synthesized in a vacuum. The PES must be done in a vacuum. They are "free standing" fullerenes, synthesized in bulk. Almost certainly not under vacuum.

I was reading DrBarr's post and it struck me that the word "fullerene" was used. I realized that I had usually seen this word in the context of carbon allotropes, e.g. C-60. I wonder if this term is maybe a bit misleading. Carbon has a valence of four while gold has a valence of one or three depending on the circumstances. It would seem that the geometric structure of an "auric cage" might have a form different than the geodesic shapes that Buckminister Fuller was going on about.

Anybody know enough about this to post some links?

Dr. R.

dehammer wrote:
"Ive yet to see meteorlogist use equations to descipe the tempature or the amount of cloud cover."

I've yet to see you provide evidence that you've ever seen anything of science.

And precisely how is it that you think we model climate on Crays? By throwing rocks at them? And how do you think the talking-head on your TV is able to say "There is a 60% chance of rain tomorrow?"

Read a book.

dehammer wrote:
"and have a basic understanding of black holes, big bang and things like that. those things i can discuss without feeling like an idiot."

I would disagree in the strongest terms. Unless the problem is your communication skill in English your understanding of black holes and the big bang is exactly -1.

Zero would mean you know nothing.
Minus one conveys the fact that what you write is incorrect ... in other words ... worse than nothing.

dehammer wrote:
"for one thing there is no need to show your arragance by calling me "boy". im 47 years old, a disabled vet, and i have a college degree. it just has nothing to do with chemistry."

If you would start acting like it and stop pontificating you would find that people would:
A) Like you
B) Respond positively to you
C) Help you learn

Many of us are here because we love science. It is a tremendous irritant to exchange information with someone who has a firewall against learning anything new.

this from someone whos answer to any explination of the black hole amounts to a religious dogma.

i never said that they dont use them, nor that physists dont use formulas. i said its possible to discuss things like these without using formulas. ive yet to see anyone making serious discussion of chemistry without using formulas. the "talking head" as you put it are well able to discuss wheather with non experts without using a single formula.

instead of attacking me for admitting that i cant discuss chemistry, why not take it back to the subject of this thread.....

OK. Please forgive me if I talk down to you, but I don't know how much you know. Metals bond very differently than non-metals. Carbon can have 4 and only 4 bonds in normal cases. Metals bonds are dependent on the oxidation state. I don't think the word fullerene has a firm defintion as it was just made up for the C60 ball, but I've heard it used for other cages. There are not atoms other than Au in these structures so for instance the Au16- has 16 gold atoms with a coordination number of 6. Hope that helps you visualize the geometry. The way they propose it, it's definately a geodesic shape. They have a small picture of it in Chemical and Engineering News May 22, 2006.

Hi DrBarr,

I didn't mean to imply that you were talking down at all. It is just that your post got me to thinking - that's a good thing!

Thank you for the input on Au-16, I will check it out.

Dr. R.