External Links
- The Reich Collection – NMR info, pKas, and other useful info
- Many useful NMR links from UC Davis
- Not VooDoo practical laboratory tips
- Common NMR Artifacts
- Drying solvents (and separate reference for amines)
- Handling of Air-Sensitive Reagents
- Chemical shifts of solvents
- And more chemical shifts of common impurities
- Correlation charts
- Titration of BuLi (from this link)
- The Chemist’s Companion (via UNR libraries)
- Sigma-Aldrich HPLC column guide
Check Your NMR Spectra
in your 1H NMR spectra, make sure your TMS peaks are less than 2 Hz and preferable ~1 Hz at half-height. (from Stephen Spain: “I always tell the students to use the TMS peak. Depending on the quality of tube and sample makeup, it should be a singlet with a width at half-height of less than 1 Hz while spinning at 20 Hz. Best case scenario would be a linewidth around 0.4 Hz, and I’ve gotten that on all the magnets in the SIL. As the shimming gets better the TMS will show Si-29 and C-13 satelites.
In VNMRJ you open your file and put the the cursor on the TMS peak and type nl dres in the command line and then press enter and that will give you the linewidth at half-height. nl forces the cursor to the apex of the peak and dres gives the linewidth.
In MestReNova the easiest way to get the half-height is to click on the drop down arrow next to the peak-picking icon and select peak-by-peak , then click on the TMS peak. From there, go to View Tables… -> then on the dialog box that pops up, under NMR, check peaks. This will give a table of all the peaks you clicked on as well as width at half-height.”)
Recommended Level of Theory for Organic Molecules
For energies and geometries of organic molecules, I am using B98D3/def2TZVP (Aust. J. Chem. 2019, 72, 563 discusses choosing from the alphabet soup of the new functionals and basis sets).
Vacuum Pump Maintenance
Welch Vacuum Technical Newsletter has a good description for rotary vane pumps.