[Question from NMRWiki Q&A forum] Varian VNMRJ 2.2D standard experiments

[nmrlearner]

Varian VNMRJ 2.2D standard experiments

Hey folks, I was wondering if anyone else has had any issues with the experiments/pulse sequences that came standard in the VNMRJ software? I am running VNMRJ 2.2D on Red Hat Enterprise, but have yet to have much success with any experiment outside of standard 1H, 13C, 19F, and 31P. Lately we have been trying to run C13DEPT, C13APT, (HC)HMBC, (HC)HSQC, and HETCOR, and have come up with nothing usable. The DEPT experiment produces the 4 expected spectra, but three are blank/noise and the fourth is just a standard carbon scan; the APT was promising, but I noticed a peculiarity about it: if I printed out the c13 spectra, the peaks were positive/negative as expected until about halfway through, where the spectra repeated itself, only upside down and in the opposite direction (as if it were simply rotated 180 degrees around the center of the spectra); HMBC, HSQC, and HETCOR all ran, but when I try to open them, I only get the message "LP analysis failed." Any attempt to display either fid or the 2D comes up fruitless (after wft each fid independently, selecting a 2D display returns the message "No 2D data in data file"). I have been able to open the HETCOR in a separate software suite (ACD labs Spectrus Processor), and the spectra there are horrific: the proton spectra is a poorly defined mess of peaks mirror imaged around the tof, and the carbon scan comes up as simply noise.

Any help you can give for how to tweak the parameters or pulse sequence is appreciated. I feel like my job depends on it!



Check if somebody has answered this question on NMRWiki QA forum