NMR Sample Preparation:

·        1-5 mg sample dissolved in 0.5-0.6 mL deuterated solvent for ¹H-NMR (16 scans)

·        10-30 mg dissolved in 0.5-0.6 mL deuterated solvent for ¹³C-NMR (256 to 1024 scans)

·        Do not use more than 0.6 mL or less than 0.5 mL deuterated solvent, either more or less solvents will cause hard to shim the instrument, could resulting bad spectra. Surely you also waste expensive deuterated solvents if you use more than 0.6 mL.

·        If you have solid in the solution, better filter it before put sample into the NMR tube. Clear solution will give you much better spectra.

A.           Warnings (Read carefully before you work with the 400 MHz NMR spectrometer)

       i.          Do not touch spinner with fingers.  Use a Kimwipe to handle spinner and clean NMR tube.

      ii.          Do not try to fit sample directly under sample injector/ejector in the autosampler!

     iii.          When using TopSpin, wait for each command to finish before inputting a new command.

     iv.          Do not use a flashdrive to transfer data!

      v.          Do not perform any command/procedure other than command/procedure list below for routing ¹H, ¹³C, ³¹P, and ¹⁹F NMR.

     vi.          For non-routine liquid NMR study including VT, 2D NMR, and solid state NMR, consult Mr. Bruce Gray first. Mr. Bruce Gray will talk to corresponding faculty member and schedule time for your experiment. DO NOT TRY UNAUTHORIZED PROCEDURES YOURSELF! One day service trip for a Bruker engineer could cost couple thousand dollars, clean up the liquid probe could cost thousand dollars plus weeks of downtime.

B.           400 MHz NMR spectrometer time schedule

i.             All NMR experiments must be scheduled through face schedule system. Currently we have AFM, XRD, and 200 MHz NMR on the system, Mr. Bruce Gray created one for 400 MHz NMR. After training and operation certification, you will be given a login user name and password for login the face schedule system. No one can perform any NMR experiment without schedule the instrumentation time.

ii.            NMR time schedule policy: weekday daytime: from 8 am to 8 pm, each booking time slot is 15 min (you can done at least 5 routine 1H NMR in 15 min), maximum 1 hour per person. Daytime long experiment (VT and solid) need scheduled through Mr. Bruce Gray. Weekend and holiday and night time are open for long time experiments, but need permission from Mr. Bruce Gray if experiments need to be over 12 hours.

C.           Operation procedure (routine liquid sample, not for VT and solid experiment): (green color, command line input; red color, TopSpin tabs)

1)      Login your own account (after you been certified, you will have your own user name and password).

2)      Start TopSpin program; ignore the “masserver message” show up on screen, just click “close” on the message window. If TopSpin program already open, skip this step.

3)      Insert your NMR tube into blue spinner (use Kimwipe to handle it, do not direct touch it with your fingers); adjust height using gauge. Do not adjust gauge position! Place sample in easily accessible position on autosampler. Use dry kimwipe to wipe clean the NMR tube.

4)      Insert your sample into NMR autosampler, type “sx  #” in the command line of the TopSpin program, where # is autosampler position of sample, then hit enter.

a)      Wait for sample to inject into instrument; an NMR sample icon at the bottom of the screen indicates if sample is in instrument; if sample is not in then a “?” is next to the icon

5)      Under “Start” tab click “Create Datasheet”; Do not change data directory

a)      “Name” = input filename (i.e. YourName_Date_SampleName)

b)      “ExpNo” = Experiment number = 1 if first experiment in this datasheet

c)      “ProcNo” = Process Number = 1 if first process of data

d)      “Experiment” click “Select” then choose method (i.e. select “PROTON” for ¹H NMR, “C13CPD” for ¹³C NMR, “F19” for ¹⁹F NMR, and “P31CPD” for ³¹P NMR);  if your method is not listed then uncheck the box “Show recommended methods” to see the full list of methods;  after method is chosen, click “set selected item in editor”

i)       If same method as previous experiment select “Use Current Method”

e)      “Title” = Description on NMR spectra; can be more detailed than filename

f)       Click “OK”

6)      Under “Start” tab click “Read Pars” (Read parameters)

a)      Select corresponding experiment method and NMR solvent you used then click “OK”

7)      Under “Acquire” tab (do not need open the pull down tabs under each tab)

a)      Click “Lock” then select the solvent you use and click “OK”; Wait for instrument to be locked

b)      Click “Tune” to autotune (atma) the instrument; Wait for instrument to finish tuning (~1 min)

c)      Click “Spin” to turn on sample rotation (do not spin if sample is not completely dissolved)

i)       Wait for sample to spin; Sample icon at the bottom will have an arrow around it to indicate sample is spinning

d)      Click “Shim” to autoshim; “topshim completed” displayed when finished

e)      Click “Prosol”; Wait for prosol command to finish (few seconds, message may flash quick)

f)       Click “Gain” to select “auto adjust receiver gain”; “rga finished” displayed when complete

g)      Optional:

i)       Type “ns” and press enter to open option to change number of scans

ii)      Type “sw” and press enter to open option to change sweep width

iii)     Type “o1p” and press enter to open option to change the spectra center

h)      Click “GO” to start acquisition; fid data will be shown while scanning

i)       “checklockshift: finished” will be displayed when completed

8)      Under “Process” tab; (note: all data processing can be done on your office computer to allow other users to use instrument, we have 5 concurrent licenses for TopSpin software. If you don’t have the software installed on your office computer, ask IT.)

a)      Click “Proc.Spectrum” to process the fid data to a ppm spectrum.

b)      Click “Adjust Phase” for phasing options if needed (>95% case you don’t need do this).

9)      Type “sx  ej” then press enter to eject the sample (sample exchange eject)

a)      Once ejection completed, use the blue button on the autosampler to rotate the autosampler until your sample can be easily removed

b)      Use a Kimwipe to handle the spinner, and place spinner back into foam container

10) Transfer (copy and paste) your data from “nmr_data” folder on the desktop of the NMR computer to the “Data_Transfer_Folder” on the desktop. After the data transfer is done, you can process or transfer your data on the Data Transfer Computer (on the right side of the NMR computer). Warning: Do not transfer data during the NMR experiments!