I've used the sublimation apparatus before and had it work, but never like this. Labmate Krista was purifying some starting material (I think it was some type of imidazole) and got some real gemstones. This first picture shows you basic air-free sublimation device.The Teflon pin and black hose on the top left of the device connect it to the Schlenk line so that the atmosphere inside the sublimator can be cleared of air and either inert gas (argon for us) or vaccuum can be maintained. Doing a sublimation under vaccuum lowers the temperature at which the sublimation has to take place. The heating mantle on the bottom, although rusty and corroded, heats the oil bath (the opaque mess in the beaker which ought to be clear and colorless) which keeps the impure imidazole hot. Under vaccuum the imidazole is below the triple point, so as it is heated it vaporizes into the atmosphere of the sublimator. The vapors are cooled on the cold finger (peice of glass sticking down into the middle of the sublimator) which is kept cold by cold water flowing through it (through the two hoses on top). Upon very close inspection the astute observer will notice that the water is flowing
backwards in this particular setup. Since the crystals Krista was growing were so spectacular, I asked if this was on purpose. Normally you would want the water to be coldest at the very bottom of the sublimator and have it warm up as it exited. Krista assured me that this wasn't skill, merely a silly little mistake. It is absolutely amazing that these crystals came out as well as they did given that the setup appears to be thrown together in someones basement using spare parts and grease someone cleaned out of their griddle. But there you have it. For those of you who are looking at the scale of these crystals, unimpressed, it is true that when most people think of crystals they are thinking of quartz crystals in their local curiosity shoppe. Well rubbish, those cyrstals took thousands of years to make, and Krista had these nailed out in less than a day; much more impressive.
I've used the sublimation apparatus before and had it work, but never like this. Labmate Krista was purifying some starting material (I think it was some type of imidazole) and got some real gemstones. This first picture shows you basic air-free sublimation device.The Teflon pin and black hose on the top left of the device connect it to the Schlenk line so that the atmosphere inside the sublimator can be cleared of air and either inert gas (argon for us) or vaccuum can be maintained. Doing a sublimation under vaccuum lowers the temperature at which the sublimation has to take place. The heating mantle on the bottom, although rusty and corroded, heats the oil bath (the opaque mess in the beaker which ought to be clear and colorless) which keeps the impure imidazole hot. Under vaccuum the imidazole is below the triple point, so as it is heated it vaporizes into the atmosphere of the sublimator. The vapors are cooled on the cold finger (peice of glass sticking down into the middle of the sublimator) which is kept cold by cold water flowing through it (through the two hoses on top). Upon very close inspection the astute observer will notice that the water is flowing backwards in this particular setup. Since the crystals Krista was growing were so spectacular, I asked if this was on purpose. Normally you would want the water to be coldest at the very bottom of the sublimator and have it warm up as it exited. Krista assured me that this wasn't skill, merely a silly little mistake. It is absolutely amazing that these crystals came out as well as they did given that the setup appears to be thrown together in someones basement using spare parts and grease someone cleaned out of their griddle. But there you have it. For those of you who are looking at the scale of these crystals, unimpressed, it is true that when most people think of crystals they are thinking of quartz crystals in their local curiosity shoppe. Well rubbish, those cyrstals took thousands of years to make, and Krista had these nailed out in less than a day; much more impressive.
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