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).

Thursday, February 14, 2008

Rube Goldberg Lives Again!

As a part of my Master’s thesis, I was tasked with measuring the rate of oxygen exchange between VO2+ and H2O18 labeled water. Unfortunately, the VO2+ exchange rate is insanely fast, much better suited to NMR based studies which were beyond the capabilities of our group. I managed to slow the exchange reaction by complexing the VO2+ with oxalate, but with a resulting half-life on the order of 2 seconds, it was still a bitch of an experiment to do. Basically the procedure involved injecting a known amount of O18 enriched water into about 1 ml of VO2(C2O4)23- solution followed by the injection of a solution of Co(en)3Cl3 to precipitate the vanadium complex and stop the O exchange. Subsequent isotopic analysis of the Co(en)3VO2(C2O4)2 gave me the exchange rate. Due to the rapid reaction rate, the time between the 2 injections ranged between 0.5 to 8 seconds and since both my hands were busy holding the injectors (a plastic syringe and a 100uL pipettor), I used a foot activated electronic timer to measure the time interval. Although my results looked pretty good, my advisor informed me that I would need to find a way to automate the timer or else no one would believe my results. I’m not sure that was really true, but when your advisor suggests something…. Since our group didn’t have a lot of money to spend, I ended up scavenging around for old switches and devices which I could take apart and attach to my injectors. After much trial and error, I concocted a device which actually worked (much to my surprise), but which was also rather frightening to behold. (I wish I still had a picture of it) The injectors were held locked into place on a ring-stand assembly with electrical contacts attached in bizarre ways so that the timer would be started and stopped by the acts of injection. Even though it appeared ready to fall apart, it worked surprisingly well, allowing me to routinely perform 0.5 second runs with reproducible results. The first time my advisor saw it, he simply smiled and said: “Nice job, Rube,” referring to Rube Goldberg, the cartoonist known for depicting ridiculously complex devices that perform simple tasks in indirect, convoluted ways. The building of that injector system is still one of my best memories from graduate school. In memory of that system, here is a link to an amusing advertisement based on Rube’s ideas.

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