#chemistry
#chemiverse
On a very related note: anyone know if using the "vacu controller" on a fancy buchi rotovap when you don't have the fancy pump with the controller attached is a problem? It is clicking a lot as it adjusts things from my not fancy pump (that I can adjust the vacuum with by hand) and I don't want to damage it. I can always do this entirely by hand if necessary. Though in that case I should maybe move the fancy rotovap out of the hood and just use one of the less fancy ones...
Just found out I wasted 3 weeks of work, a significant amount of solvent and other reagents because the commercial starting material is not what the bottle says it is to add insult to injury what is in the bottle isn't even clean, there is at least one other thing in there.
Hilariously (not really) the only reason I determined this was because I'm making something from the literature and none of my spectra were matching close enough. Went back to the start to check and remade the first step, it produced the same wrong thing. Tried some other conditions, same deal. Finally took an NMR of the starting material today.
I'm fairly familiar with the concept of automation in labs (my supervisor has two different King Fisher automation systems, I've toured UCLA's high throughput drug discovery facility and talked with the director, use an automated NMR on a weekly if not daily basis, etc) and I have some serious questions with this article.
Starting at the end: I really don't think this is going to "democratize science" unless people are renting out time on their already built set-ups to any random person on the street because the barrier to entry is absurdly high in terms of cost of the machines and I doubt the "AI" powered ones are going to be cheaper.
https://www.npr.org/2026/06/05/nx-s1-5846973/ai-science-robots-risks-experiments-gingko-bioworks
the paper from the company in question: https://www.biorxiv.org/content/10.64898/2026.02.05.703998v1
A post-doc once remarked when I was a grad student that "one nitrogen makes the synthesis interesting, more than one is a pain in the butt" and I'm feeling that right now.
Is this the same compound that I made previously? I dunno, the NMR is slightly off, but nitrogen potential for protonation and hydrogen bonding, maybe the fact I had EtOAc in the NMR last time skewed the location of a few peeks? Maybe the fact I ran a column under basic conditions (NH4OH so won't show up in the NMR) rather than neutral ones means my NMR is off from the literature?
(I'm feeling this about multiple compounds recently FML)
When you go to get something out of the cabinet (which turned out not to be there anyway) and discover something else is A Problem.
This was the boron tribromide with the "use in three months of pack date" that I was shipped in July of last year. I haven't touched it since maybe late September, at which point it looked pretty normal. The bottle itself is inside this secondary container and I'm a little worried what it's going to look like when I open it...plastic cap maybe totally disintegrated?
Heads up for chem people looking for free stuff: I asked Macherey-Nagel for a sample of their two color TLC plates (they fluoresce in 254 & 3something nm, sounds cool!) by sending a comment in to their "you have questions about this product" form and someone got back to me and said they would ship me a box of them. Usually you get 1-3 plates for samples (a box usually has 20 if we're talking full sized plates) so I was skeptical, but I just saw the tracking information and it says 4 kg, which is about what a full box weighs...
If they make anything you'd like to try worth asking for samples I guess?
When the compound is pure: 1 spot on TLC
When the compound comes off the column: 2 spots on TLC, one is the starting material
When the reaction mixture is checked: 1 spot on TLC
Apparently something in the reaction mixture causes the product and starting material to run together on TLC (and on the column). This is the sort of thing that makes me want to throw test tubes at the wall just to hear the sound of breaking glass.
(the situation is actually a bit more complicated than what I've described here, so please no suggestions)