This blog is my attempt to reconnect with the world of chemistry. I have a PhD in Inorganic Chemistry and make a living doing research for a large company in Michigan. As times have changed, that company has changed its focus and I no longer have as much chance to do the basic, fundamental research which I most enjoy. Through this blog, I am hoping to recapture the magic which I felt during my graduate (and undergraduate) days in college. Expect topics on chemistry and alchemy along with some non-chemistry related items which I think might be interesting.

"The chymists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasure among smoke and vapour, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I would change places with the Persian King."

Johann Joachim Becher (phlogistonist)
Acta Laboratorii Chymica Monacensis, seu Physica Subterranea, (1669).

Tuesday, April 29, 2008

Elemental Paradigm

No doubt everyone has already heard that a new element has possibly been discovered with an atomic number of around 122. Typically new elements are produced by smashing large nuclei into each other at high velocities. The resulting new elements are so unstable that we often only know of their existence by their decomposition products. Today’s new element appears to be a little bit different. It was found just lying around amongst thorium atoms and supposedly has a half life of over 100 million years. This surprising stability is due to the element’s proximity to the so-called “island of stability” for nuclei. It’s been years since I took a nuclear chemistry class, but the one thing I do remember is that protons and neutrons in a nucleus have to occupy quantum shells in much the same way as electrons do within an atom. And just like with electrons, a nucleus is most stable when its “shells” are completely filled. For a much better explanation go here.

Now you know that everyone is going to start searching through piles of thorium, uranium, and anything else they can get their hands on in order to find more elements. And it wouldn’t surprise me at all if it turns out that several superheavy elements have been all around us all this time. We’ve just never gone looking in the right way before. I love these kinds of paradigm shifts. (I’ll probably never use the term “paradigm shift” again in this blog) For example, back in the 60s, it was thought that molybdenum could not exist in water in the +4 oxidation state. All sorts of attempts were made to synthesize it. Reducing aqueous Mo(V) either chemically or electrochemically only produced Mo(III). Oxidizing aqueous Mo(III) either chemically or electrochemically produced Mo(V). Adding MoCl4 to water resulted in its immediate disproportionation into Mo(III) and Mo(V). After a decade of assuming that aqueous Mo(IV) didn’t exist, someone discovered that if you mixed Mo(III) and Mo(VI) together in the right proportions and you waited long enough, you would end up with a dark liquid which could be separated on an ion exchange column. The reddish fraction turned out to be Mo3O44+, a stable form of Mo(IV). Then it was discovered that you could mix Mo(III) and Mo(V) and get the same thing, if you gave it a day or two and used ion exchange resin to clean it up. Then Mo(II) and Mo(VI) worked, and then….. Well, soon it became obvious that pretty much everything gave Mo(IV) if you knew what you were looking for. It’s amazing how science works.

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