hypervalent_iodine

1H NMR (tell them that your sample is soluble in DMSO and MeOH and not chloroform), 13C NMR if possible, high res mass spec and maybe see if they can run a GC-MS on it.

No, you just need to get the right tests done on your samples.

Because they are toxic.

You might find it difficult to send to anyone overseas, since you have absolutely no idea what it is. Customs officials tend not to like mysterious white powders. The appearance of the crystals is not unusual. There a few compounds I remember having encountered that look similar, though they are not something you would really want to use for the purposes you state.

Your best and easiest bet is to get a lab from where you are from to do the analysis. IIRC, of the chemists I know of who frequent here, none are from Canada, which makes it difficult (ignoring the fact that it would probably not be allowed anyway). Your PIXE results seem a bit odd to me, but I am by no means familiar with that type of test. It says there is sulphur in there, so it could still be methionine. Again, though, it is impossible to tell without some more data.

As JohnCuthber said, speculating is not going to get you anywhere in terms of working out what it is. You need to get tests run on the sample. Also, I was asking what you want it to be able to dissolve in?

It's hard to say without knowing where you are, although even then I would not have anywhere to recommend for getting a sample tested. You might be able to find a pharmaceutical testing company or some other analytical lab that will do the tests for you. Also, dissolves in what?

The results of that test were too convoluted from the water in it to really tell much of anything without calculations, so I ignored it since I was posting on the run and not near a calculator. Edit: I just did a couple of calculations to work out the true oxygen percentage assuming that all of the hydrogen was from water and the results don't really make much sense to me. Perhaps you could shed some more light on it, as I am not terribly familiar with this type of test.

Can I ask if you have any inclination at all as to what it might be? As in, are you able to narrow it down to a certain type of chemical or did you literally just stumble upon a bag of unlabelled white powder? Your best bet in terms of characterisation is to contact a lab willing to run some tests for you. You'll want 1H NMR and mass spec at least and perhaps a GC-MS trace to ensure purity, etc. It will cost you money (though I have no idea how much, but it will give you your answer. If you can do that, show your results here and we/I can take a look at them for you.

Yeah, as I said, there are a bunch of chemical tests you could do. Yielding the free base would be useful though, because I am now more convinced it may be the N-acetyl derivative and doing so would eliminate or confirm at least one possibility.

First things first, and excuse my alarm here, but WHAT WERE YOU DOING EATING UNKNOWN CHEMICALS?! Honestly, what were you thinking? Touching them with you bare skin is bad enough, but eating them is just plain silly. I hope I misinterpretted something when you said that it tastes salty and that you weren't truly eating unidentified substances in a lab, but if you were, please don't do it again. It's for your own good. Anyway, since chemists don't go around eating chemicals as a rule (no really, it's a rule), telling us what it tastes like isn't very helpful. To be honest, a physical description of what a compound looks like isn't very useful for identification purposes. Your characterisation data suggests your crystals were very wet, so it's not very helpful either, except that it tells you it is hygroscopic. This makes sense given your info on solubility. I would recommend running it through a GC-MS and getting a proton NMR. That will tell you what you have. 100 degrees C? That's not that low for an organic compound and you should have no trouble figuring outthe m.p. if it's in that range. That it went brown means it decomposed (which isn't melting), so you have likely ramped the temperature up too high, too quickly. It does sound like what happens when you heat sugars up, though (think toffee), so I'm suspicious you have a HCl salt of an amine derivative of some kind (maybe glucosamine hydrochloride). There are a few chemical methods to test for this, but they still won't give you exact information and getting spectral data is really much faster. To conclude: I think what you have is the hydrochloric salt of an amino saccharide. Having said that physical appearance is useless, I'm going to make a hypocrite of myself and say it looks like D-aminoglucosamine hydrochloride, having had worked with it before. Get GC-MS or mass spec data and an NMR spectra to confirm. Finally, do not eat chemicals in the lab. That is a bad, bad idea. Just a quick edit: it may also be N-acetyl glucosamine or similar.

Psht, that method is painfully outdated to say the least. There was a Japanese group a few years ago who used an eye of newt interdimensional plane transfer catalyst (iPTC), which worked really well. Yields of about 85%, with a 95% ee (if the sword spins clockwise, it's the ®eally bad evilantiomer and if it spins anti-clockwise, it's the (S)uper bad evilantiomer). Oh yeah, and it has to be done by this guy:

Maybe I'll go to a neo-nazi convention and try to shift the equilibrium to the left.

http://www.scienceforums.net/topic/17898-the-chemistry-latex-tutorial/ There is no excuse!!

Ah, okay, fair enough. Well, I don't really know much about it, but it doesn't sound terribly boring, so I might have a go at reading about it and see if I can make it any clearer for you. Unless someone else beats me to it, anyway.

My post is still factually correct. It does not need to be soluble to dissolve in some cases. This is not true for all or even most compounds, but it is nonetheless true. If you read the entirety post #29, I did go to some effort to explain that, which you appear to have ignored. The rest of post #37 still stands with all your editing, so feel free to reply to it.

Might want to check who actually wrote that post. Hint: it was me. You can dissolve something without it being soluble in the solvent you are putting it in. This, however, is completely aside from the OP. If you would like to discuss it further, please start a thread about it. In fact: Greg, you appear to be going in confusing circles with whatever it is you are trying to say. At this point in the argument your only reproach is to argue semantics for purposes I fail to understand. Do you still have an argument to make in light of what everyone has said here and if so, would you be so kind as to summarize it for us so that we might get back on topic?

Is this a homework question? In either case, we're not going to write an essay for you 'in detail'. Could you please explain what it is you don't get and members here will address the specific issues. My advice would be to start your search with this website. To get you started, here's a paper I found by using the key words 'macrolides' and 'hepatotoxicity'.

My assumption was that the two silver atoms were still bound to the central sulphur the same way as in Ag2S. Either way, it doesn't make chemical sense (and is also not bond breaking, as mentioned in Greg's post).

I'm not talking about water (and have never even mentioned it in any of my posts), I'm talking about ammonia. And no one is talking in absolutes, we're talking in chemistry, where negligible molar solubility is typically described as insoluble. That's because the ammonia reacts with the copper hydroxide, whereas the water does not. You're talking about two different compounds with very different reactivity profiles, so I quite honestly do not understand what point you are trying to drive here. Copper (II) is right on the borderline of being a hard and soft acid and will react accordingly with a hard base such as ammonia. Silver is a soft acid - i.e. it accepts electron pairs and will form complexes in which the predominating acid-base interaction is covalent in nature. Typically we say that soft acids will only react with soft bases and hard acids with hard bases; that being said, ammonia can, in some cases, donate its lone pair of electrons to form a covalent bond with a soft Lewis acid such as Ag+. This is why some silver halides react with it. Silver iodide does not react with ammonia though, as John noted. This is because the iodide ion is a soft base. Bromide and chloride ions are not. Sulfur is another soft base - do you see where I am going with this? This is correct. Solubility should not be confused with the ability for something to dissolve. As noted, there are plenty of compounds that are insoluble in a given solvent, but will still dissolve due to various reactions that take place. Firstly, your initial sentence in this post is rather unnecessary. This isn't fight club, it's a discussion board. I understand there has been a deal of hostility, but there's no reason to try and encourage more. Secondly, the only person who has talked about the existence (Ag(NH3)2)2S is you. Ignoring the fact that you have written it chemically incorrect, I am incredibly skeptical that such a compound would exist; talking about whether or not it's soluble in ammonia is therefore a pointless endeavor. Ag2S won't react with ammonia, nor is it soluble in it. John and I have tried saying this to you a number of times in a number of ways already.

Greg, ammonia doesn't react to form a complex with silver sulphide (as I think John pointed out quite some posts ago), so your argument is still moot. It doesn't matter how many posts you spend arguing semantics, the fact remains that ammonia does not and will not remove silver sulphide from silverware.

Why would I spray DDT on myself or my nonexistent children? I live in a developed country where I can quite easily go and buy Aeroguard. Kind of makes it a bit of a pointless endeavor for me. And who said anything about spraying it on people, anyway? Only you and that strawman of yours. I'll agree that DDT shouldn't be used everywhere and anywhere - and it's not, either. It is used in cases where other current alternatives simply are not viable. A free supply of aeroguard? Do you realise how expensive that would be? Pyrethoid insecticides were great in the South Americas, but have not seen as much success in Africa. There is no such thing as a one method fixes all type approach in this, since there are many, many species of mosquito and many parasites to go with them. And as for being "completely" non-biodegradable: DDT has a half life from about 28 days and up, depending on where you spray it, etc. Re. thalidomide: Regulatory bodies worldwide stepped up their game in terms of what tests they required - even America, who actually made the smart enough to say no thank you to thalidomide - but its biggest effect was the recognition by organic and medicinal chemists that stereochemistry plays a massive role in bioactivity profiles, etc. The other enantiomer of thalidomide is actually harmless. It's metabolised back to the not-so-nice enantiomer in the liver, but still. Anyway, there's no point in being caught up in the examples, as they is irrelevant to the argument. My point was this:

I put myself through days - no, weeks of mental anguish trying to decide upon my signature. I wanted something deeply meaningful and truly reflective who I am as a person, which I suppose boils down to 'morally compromised', given the result(s) since I started using the feature.

Just a quick note about DDT: Do you realise that DDT is currently in use in impoverished regions of Africa for use as a mosquito repellent? It's not sprayed on plant matter, simply on the outside of huts (IIRC). It saves thousands of lives that might otherwise have been taken by malaria - or it would, if government legislation didn't make it so ridiculously hard to obtain, forcing the idea to be almost completely abandoned. Just because the use of technology is detrimental when used in one context does not make it so in others. Thalidomide is another such example. As a treatment for morning sickness it was disastrous, but it is quite safe and effective for use in treating leprosy. Censoring the development of technology on the basis of it having damaging side effects for one particular application is incredibly blind-sighted and ultimately more detrimental to human society, in my opinion.