hypervalent_iodine

I'm not sure I quite understand your question. Are you asking why aromatic compounds tend to be planar? The rigidity of compounds such as benzene is in fact necessary for them to be aromatic. If benzene were bent into conformations such as those seen in cyclohexane, the pi orbitals would not lie in the same plane and thus the electrons in them would not be able to delocalise around the ring, which would cause for it to cease being aromatic. I'm not sure if that answers your question or not though, so perhaps your could rephrase it?

As I said, I myself have not used it. The general opinion of it is that is not good for small scalee preps, only large ones. There are a number of ways that you can remove solvents without product decomposition. Water for instance may be azeotropically removed by adding toluene. I'm not sure what you mean by removing organic solvents from water. Most organic solvents do not mix with water, making extraction quite simple. Do you have high vacuum pumps with a manifold set up at all? That's the usual alternative to a lyophiliser. Honestly, if I had the choice over the biotage and a lyophiliser, I would most definitely pick the latter, simply because it has a more general applicability.

This argument can only hold if you pre-define what dark energy is. Since you yourself have admitted we don't know what it is, simply that it exists, this entire paragraph is moot.

I don't know much about Genevac, but our lab does happen to have a Biotage. I haven't used it myself, however the general opinion of it seems to be that it's really only good for large scale preps. Our lab, which does a lot of natural product synthesis and as such, a lot of very small scale synthesis (I often work with 10mg of product or less for reactions) doesn't tend to find too much use for it. That being said, it is good at what it does, when you can do it. Is all you're trying to do remove solvents with high boiling points? Have you considered distillation?

Hm, well there you go. We were taught quite emphatically by our professors that it was certainly not a spectroscopic method and to never call it as such (it was in the same category as drawing pentavalent carbons on exam papers). Edit to add: Upon further investigation I have found out that it used to be a form of spectroscopy by virtue of the way by which data was recorded (on a photographic plate), but is no longer considered to fall under that definition since MS no longer uses the same method of output. Spectroscopic techniques, so far as I am aware, are strictly those that measure interactions between matter and EMR. Since MS doesn't do this per se, it is not considered a spectroscopic technique.

I don't know about better, but they certainly that great depending on what quantities you're getting on your hands. Cleaning collection vials, I usually have to change gloves every 10 or 15 tube before it tears up and it doesn't take long for the glove to start expanding and acetone to start seeping through them. The lab I work in, which is a synthetic chemistry lab, only has nitrile gloves in stock; I suppose it's fine as long as you change gloves regularly and avoid getting it on your gloves as much as possible.

As John Cuthber said, you can get dimerization, which will give you (usually) low intensity peaks of high mass. As a side note, MS is not a spectroscopic method and as such is called mass spectrometry, not spectroscopy.

Might I suggest getting a newer text book, or at least using the internet to check your information? A lot has happened since the 1960's.

I would cross out 6 also. I assume by 'inert' you refer to the noble gases? Xenon, for instance, has been known to form hypervalent compounds since the middle of last century. You might also cross out 14, or at least redefine it to include only the 20 standard amino acids.

You're right, it would lead you somewhere, but it sure won't lead you to boron chemistry. Moontanman, I don't know much about this area of chemistry, but a quick search of boron polymers gave me these links: http://www.tcm.phy.cam.ac.uk/~pdh1001/papers/paper7/ http://www.iupac.org/publications/pac/1991/pdf/6303x0407.pdf http://pubs.acs.org/doi/abs/10.1021/ba-1961-0032.ch027 Also, this book: http://books.google.com/books?id=0_yQXXMFQrcC&dq=Macromolecules%2BContaining&ie=ISO-8859-1&source=gbs_gdata

Although very much based on certain concepts of chemistry, I suspect that what you will find is that biochemistry as a whole involves very little in the way of chemistry and significantly more in the way of biology. What you may be looking for is biological chemistry/chemical biology major, which tends to put more of a even focus on the chemical side of things. For instance (and this is just an analogy from a a few courses I did in my undergrad), in biochemistry you would learn about beta oxidation in terms of, 'this is what you start with, this is what happens at the end and it is done by this enzyme". In a more chemistry focused major, you would learn the chemical mechanisms behind that. As CharonY said, you are not locked into any area because of your major. You could easily do a biochemistry major or a chemistry major and end up working as either, or even both. It might be worth while if you have an interest in both chemistry and biology to take on a dual major or simply do courses pertaining to both so you have an in depth understanding. I personally found it much easier to comprehend and remember biochemical pathways by learning the chemistry behind it, though that's not to say you will be the same.

There are also hypervalent compounds, which are stable sue to the nature of their bonding structure and the electronegativity of the associated ligands. If I have time later, I will expand on that some more.

As with the above posts, PhD's are very flexible and the amount of time you take to complete them is completely up to you. That being said, in Australia almost every PhD student studying some branch of science will have theirs within 3.5 years. This is simply a result of the fact that you can't get scholarships for any longer than that time (for international students, it's 3 years) and you have to start paying tuition, so many are forced financially to complete within that time frame.

As a manner of convention, in chemistry we never express reactions as: A + B = C We use arrows to signify the outcome of a reaction: A + B --> C To answer your question, though I'm not sure I agree with your reaction, the product you've drawn would be called 1-((4-aminobutyl)amino)-3-hydroxy-1-oxopropan-2-yl hydrogen phosphate (according to ChemBioDraw).

Really? I'm not doubting that that's the translation, but the comment makes no sense. Unless I'm missing something?

Do you think you could translate this into English? Not meaning to be rude, but I couldn't get anything to work out what this was saying, and I can't exactly help you if I can't understand you. In answer to your initial question, it boils down to their respective ionic radii. Since this may be a homework question, I will not answer it specifically, but I recommend you look up what an 'ionic radius' is.

The short answer is, no. You can, however, selectively funtionalise the ends of a carbon nano-tube. Here are a few papers, though you may not have access to all of them: http://pubs.acs.org/doi/abs/10.1021/ja0423670 http://onlinelibrary.wiley.com/doi/10.1002/chem.200204618/full http://onlinelibrary.wiley.com/doi/10.1002/smll.200400118/full Why exactly would you want to do this (functionalise the ends of a graphene sheet and turn that into a CNT, that is)? ETA: I also found this, which I think you will have access too: http://snml.kaist.ac.kr/jou_picture/PDF/85.Tailored%20Assembly%20of%20Carbon%20Nanotubes%20and%20Graphene.pdf

I've noticed a trend over the past few months in some of the newer members posting here and in some of the other board, which is that they appear to think that they have the right to information without anyone questioning what they plan to do with it. So I thought I would post this thread, which more or less reiterates some of the T&C as well as various member posts. Many of the people who answer questions in this forum are professionals, students at university/college/etc., or well informed hobbyists. As such, when people ask questions here, we have a responsibility to ensure we are not providing them information that could potentially lead to the production of illicit substances or the production of goods (be they chemicals or otherwise) that may cause harm. Thus, if you plan on posting such a question in these forums, you should be wary of the following: 1.) This is the internet and as such, we do not automatically know who you are, your level of expertise or what kind of equipment you have access to. Do not get frustrated at members who are asking for more information on these points if what you are asking fits into the above category. We need to know that you know what you are doing, especially when it comes to synthesising chemicals. A lot of synthetic protocol seem a lot easier than they appear on paper and making them can involve some serious risks. If you are not practised enough, or do not have the right glassware, etc. at hand, this will almost certainly lead to an accident and you could potentially get quite hurt. 2.) This leads me to my next point, which is simply an extension of 1.) - if you are asking members here to provide with information on how to synthesise compound X, and compound X is in some way dangerous or could be used to make illicit substances, we will ask you why you want the information. If you want your question to be answered, you have to tell us why you are asking it in the first place or we will not provide you with any information. This does not, however, mean that you can haze over the details with a blanket statement such as, 'I'm doing this to cure cancer.' Firstly, it does not address the issue of exactly what you are doing with the chemical you want synthesised and secondly, comments like that will attract a lot of questioning and suspicion. 3.) On that note, in some cases we will make other suggestions that could better solve your problem. Not answering the queries of members and then getting frustrated at them for not answering your initial question only serves to make a long and unnecessarily bitter thread. 4.) Lying to us about who you are, or only providing half the truth is not the way to get help. More often than not, these sorts of lies will be caught and you will be treated with suspicion. We have a number of backyard chemists who frequent this site, and I for one am always happy to help them when they have questions. My point is that we don't provide answers exclusively for people with PhD's or what have you, so lying about having one to get an answer is pointless. 5.) As mentioned, many of the people who frequent this site are trained professionals. These people can spot questions relating to the production of illicit substances a mile away, no matter how you dress the post. My point is, don't kid yourself into thinking that you can fool these people into giving you this sort of information. They will not and you will likely get yourself a ban. With all that said, we are always happy to answer questions here. Just be aware of the above points if the question you are asking is for the production of certain chemicals, etc. and everyone will get along fine. Happy posting!

Not quite. It's actually because ZnCl2 is very soluble in water and will absorb it readily from the atmosphere. So if you weigh it while hot, water will begin to condense in your flask and contaminate your sample. Weighing to cold ensures firstly, that your getting an accurate reading, since you will accrue water mass as the sample cools, and secondly it ensures your sample is at least moderately dry and that it does not react with water to form hydrates. Well done, sir. You beat me to the punch in a matter of seconds.

My mistake. I had meant to write mid-last century. I guess that's what happens when I try posting on threads before the morning coffee.

"Van de Waals-ish" compounds, also known as hypervalent compounds. In fact, I would posture that the discovery of XeF2 early last century was the key compound leading to the definition and quantum mechanical description of such, but that's somewhat off-topic.

Mass is a more general term referring to how much of something you have. Molar mass is the mass of a compound per mole of substance. As for your first question, although I could sit here and detail how to do it, it's much easier for you (read, me) to read this website, which goes through it quite well.

Honestly, there are just so many. And some of them aren't even chemists, but are instead pesky physicists. I suppose one can't go past the works of Pauling, since he developed the currently accepted theory on chemical bonding. In that line, you could also name every other Chemist/Physicist with a fundamental theory associated to them (Huckel, Aufbau, etc.) Mendelev, who is of course the father of the periodic table. Moving more into organic chemistry, there is Woodward, who in conjunction with Hoffman described a set of rules to predict the outcome of pericyclic reaction, as well as about a thousand other things. Every other chemist with a named reaction that has stood the test of time (Grignard, Diels, Alder, Friedel, Crafts, Grubb, etc.). Someone who I think deserves special mention is Emile Fischer, who worked out the relative stereochemistry of all of the basic monosaccharide units in the 1800's, without NMR or XRD, AND was later found to have correctly denoted their absolute stereochemistry (though that part was pure luck). Honestly, there are too many for me to sit here in name.

You shouldn't let my prolific posting fool you into thinking that it is a measure of my talent! I do alright though

An alkali metal is an element from group I on the periodic table (Li, Na, etc.), where are alkali earth metals are group two elements (Be, Mg, Ca, etc.).