DFT calculations of 1H chemical shifts, simulated and experimental NMR spectra for sarcosine

Chemical shifts δ have been calculated for the 1H attached to carbon atoms of sarcosine. Eight levels of theory within the DFT approach were used, mixing the four functionals B3LYP, PBE, OPBE, PBE0 and the two basis sets 6-311++G∗∗ and pcJ2. Boltzmann weighted isomer effects have been evaluated. By comparison of the 1H NMR spectrum simulated from the calculated δ and the experimental one that we acquired at 300 MHz, the B3LYP/6-311++G∗∗ calculation was seen to be a good compromise between accuracy and cost. Zero-point vibrational corrections, estimated using a second-order perturbation approach, increase the agreement with experiment.