I mentioned recently that my girlfriend joined Steemit so I have more time for posting and today I had a pretty full hood so I snapped a picture and will give a tour! If organic chemists were artists, their artistic masterpieces would be molecules and their studios would be hoods.
A hood, or fume hood, is a necessary part of a lab that keeps chemists safe by sucking away volatile solvents and toxic fumes. They are similar to what are over ovens to vent fumes in case you burn your supper. The main difference is that there is a significant amount of working area that is isolated from the air in the lab. This allows you to do stinky reactions while keeping your labmates safe from the resulting odours.
Starting at the top left, I have a brown reaction running in a 250 mL rounded bottom flask. This reaction is a Sonogashira cross coupling in which an aryl iodide is being coupled to a terminal alkyne. Next to it is a second flask in a shiny metal bowl. This flask has a methyl ether cooling to -78 °C for demethylation using BBr3. In the shiny bowl is acetone and dry ice. The dry ice evaporates at -78 °C which causes the acetone it is submerged in to be at a constant -78 °C just like ice cubes keep a glass of water at 0 °C by slowly melting. If you submerge something in it you will see a lot of bubbles as the dry ice evaporates until the object reaches -78 °C.
You may notice that there is a big white stopper (called a septum) at the top of both flasks with needles attached to tubes. These reactions are sensitive to the air (the first being oxygen sensitive and the second being water sensitive) and must be kept under dry nitrogen. The tubes lead to a supply of dry nitrogen which keeps the flasks under a positive pressure (higher inside the flask that outside) of nitrogen. When the flasks are sealed like this it is possible to add solvents and reagents by needle through the septum (big white stopper). In the bottom right you can see a syringe that was used to add solvent (dichloromethane in this case) to the reaction via a long needle.
Both reactions are fixed with clamps above odd looking white pedestals with knobs. These are stir plates. The left knob spins a magnet inside the stir plate which then spins a magnetic stir bar that is inside the reaction. this keeps the reaction well mixed. The right knob is heat. These reactions are at room temperature and -78 °C so the knobs are cranked to zero.
The red bottle is BBr3. This reagent is particularly dangerous and fumes in air producing HBr, a strong acid. This produces a white smoke anytime this reagent comes in contact with the atmosphere which looks really cool, but is a bit dangerous. This bottle can only be opened in the hood. Highly reactive reagents like these are necessary for reactions with relatively inert functional groups like ethers.
The rest of my hood is littered with rounded bottom flasks containing compounds I've made and some fractions from a column, but I think I'll stop here for now. If you have any questions, ask below! Coming soon is a post detailing my research. Stay tuned!
My hood is cleaner lol