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RESEARCH PRODUCT

Comparison of different theory models and basis sets in the calculation of 13C NMR chemical shifts of natural products.

Giuseppe BifulcoRaffaele RiccioDario DucaPaola CiminoLuigi Gomez-paloma

subject

natural productBiological ProductsMagnetic Resonance SpectroscopyBasis (linear algebra)Databases FactualChemistryChemical shiftstructure elucidationStatistical parameterGeneral ChemistryGIAOCarbon-13 NMRQuantum chemistryNMRModels ChemicalComputational chemistryAb initio quantum chemistry methodsab initiocalculationData Interpretation Statistical13CNMRQuantum TheoryGeneral Materials ScienceDensity functional theorydensity functional theorySoftware

description

The influence of the calculation method in mimicking experimental 13C NMR chemical shifts of 15 low-polarity natural products singularly containing 10–20 carbon atoms was investigated by employing different quantum chemistry approaches and basis sets, both in the preliminary geometry optimizations and in the following single-point 13C GIAO calculations of the NMR chemical shifts. The geometries of the involved species were optimized at the PM3, HF, B3LYP and mPW1PW91 levels whereas the 13C NMR parameters were determined at the HF, B3LYP and mPW1PW91 levels. Different combinations of basis sets were also tested. The consistency and efficiency of the considered combinations of geometry optimizations and GIAO 13C NMR calculations were thoroughly checked by the analysis of statistical parameters concerning computed and experimental 13C NMR chemical shift values. Copyright © 2004 John Wiley & Sons, Ltd.

10.1002/mrc.1410https://pubmed.ncbi.nlm.nih.gov/15366038