pyridine

The ligand that I've been working on (the A+B = C+D thing in a previous post) has been one tough cookie to crumble. The main reason for this is (I think) that the solubility of the starting material is pretty poor in THF, which is the solvent of choice for analogues of the target compound. The smart move here is to switch to a better solvent. After testing solubility of the starting material in a number of different solvents (THF, fluorobenzene, nitromethane, glyme, pyridine, DMSO, and methylene chloride) it turns out that this stuff is soluble only in pyridine and DMSO. DMSO is a great solvent if you never want to isolate your product again. Everything is soluble in DMSO. I'm soluble in DMSO. It boils somewhere up around 180C which doesn't really make it strippable. This leaves pyridine, which is what I've been using, but I can't say I'm terribly excited about this either. It stinks(if you can smell it, you're not working carefully enough), its tough to dry, tough to vacuum transfer and is particular bad for gentlemen such as myself, if you know what I mean. (For those that don't know, pyridine could be used as a very effective male sterilizer, so long as you don't mind not having lungs, a liver, or several other major organs as well.) The upshot of all this is that when I get frustrated trying to get the pyridine to pump over in time for me to get down to my NMR time, I can't throw the bomb to the floor in frustration for consideration of my future kin.

in the opposite direction

I've spent the last two weeks working on new compounds, one is a variation on a ligand we've been using here, and the other is a new metal complex. After a considerable amount of effort I have made (I think) both of them, but they are so unstable they fall apart into starting material. That is to say, there is more than one way to make these things. Say I can get complex P (the desired product) either starting with A + B or C + D. What I have essentially done is found a way to fleetingly make P from A + B but ultimately what I have done is to make C and D from A + B in a really fantastically expensive and time consuming way. Not that this is uncommon, but to have it occur to two different projects at the same time is extraordinarily frustrating.

steady progress

I did get my line back from the glassblower and in fine condition. I reset all the clamps and got the pump oil warmed back up. All the pins are greased, the inert gas manifold now has an inlet and an outlet at the opposite end (as it should) and a shiny new Hg bubbler/monometer vented (through a sulfur trap of course) up into the hood. Proffesor Heller was not particularly pleased about the Hg, and pointed out (rather after the fact) that we had some stop-flow valves in the lab for that purpose, but I don't have a port for a pressure gauge, nor do I really want one, so the Hg monometer still serves some purpose. Enjoy this picture of my hood, and notice that this is as clean as its ever going to be for the rest of existance. The line is repaired, the inside is clean from when the sash was fixed. (Those stains are happy accidents of years gone by.) A fix on the fridge is in the works and soon my chemistry might even start to work again. Keep your fingers crossed.

wrong

Things have not improved. Our chemical storage refrigerator stopped working over the weekend. There are two reasons to keep chemicals in a cold storage refrigerator: it will decompose to something else or it has a very low boiling point and could generate enough pressure in a closed container to explode at room temperature. This means that you need to have an explosion-proof fridge, just in case. And we did, (luckily nothing blew up) but it also makes repair or replacement a much more expensive proposition for the lab.

In better news I should get my line back tomorrow.

sash troubles

The cable which supports the counter weight for the sash on my fume hood snapped yesterday. This is a minor inconvenience compared to the other myriad of poor fortune which has befallen the lab in the last week. My Schlenk line is going to the glassblower on Tuesday (hopefully it will be in tip top condition upon its return.) To boot, Jake's line got completely wrecked and Derrik's sash had a crack in the safety glass, which the fellow's who came to fix my sash insisted also needed to be taken care of by ES&H regulations, so his line is down as well. For those of you keeping score, that leave two functional Schlenk lines - one of which is only half functional - for 8 lab members. Oh - and the facilities manager who came to check up on the sash progress noticed that some of the clamps we were using to hold the Schlenk lines up were wrapped in asbestos tape, so they were confiscated. Goody goody. Things can only improve from here.