April 26, 2004

Derek Lowe meets Hydrogen

Wonderful entry in Derek Lowe's blog In the Pipeline He is a pharmaceutical chemist and sometimes relates "interesting" lab events. Today's is a good one... bq. I've never liked hydrogenation rooms. For my non-lab audience, that's where we keep the equipment for running reactions in pressure vessels under hydrogen gas, always with some sort of metal catalyst to make the hydrogen come in and reduce things. It's about as close to witchcraft as modern organic chemistry gets. bq. And it's just those ingredients that make me nervous. Big metal cylinders of hydrogen gas can't help but bring to mind visions of the Hindenberg, for one thing. If something fails on the apparatus, it generally fails with spraying, fizzing, and/or flames. And any hydrog room that's been around a few years invariably picks up black residues of spilled catalyst everywhere. It's in the cracks of the lab bench and in the fittings of the equipment. bq. You want to be careful with that stuff. Most of the time, we use powdered charcoal impregnated with palladium or platinum, which looks like, well, charcoal. But under the right (um, wrong) conditions, it can come to life like you wouldn't believe. In the presence of hydrogen gas and some air, such as when you mess up and open the flask, the powder gets so hot it glows bright orange. It looks like it's just come out of a furnace, and that's about when it ignites your reaction solvent. Then you might as well get out the hot dogs and suntan lotion, because the fireworks are going off already. Check out the rest of the story - it's a good one... Posted by DaveH at April 26, 2004 11:16 AM