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Chemical Shift Tensors of Cimetidine Form A Modeled with Density Functional Theory Calculations: Implications for NMR Crystallography.
J Phys Chem A. 2020 Apr 23; 124(16):3109-3119.JP

Abstract

The principal components of the 13C chemical shift tensors for the ten crystallographically distinct carbon atoms of the active pharmaceutical ingredient cimetidine Form A have been measured using the FIREMAT technique. Density functional theory (DFT) calculations of 13C and 15N magnetic shielding tensors are used to assign the 13C and 15N peaks. DFT calculations were performed on cimetidine and a training set of organic crystals using both plane-wave and cluster-based approaches. The former set of calculations allowed several structural refinement strategies to be employed, including calculations utilizing a dispersion-corrected force field that was parametrized using 13C and 15N magnetic shielding tensors. The latter set of calculations featured the use of resource-intensive hybrid-DFT methods for the calculation of magnetic shielding tensors. Calculations on structures refined using the new force-field correction result in improved values of 15N magnetic shielding tensors (as gauged by agreement with experimental chemical shift tensors), although little improvement is seen in the prediction of 13C shielding tensors. Calculations of 13C and 15N magnetic shielding tensors using hybrid functionals show better agreement with experimental values in comparison to those using GGA functionals, independent of the method of structural refinement; the shielding of carbon atoms bonded to nitrogen are especially improved using hybrid DFT methods.

Authors+Show Affiliations

Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.Department of Chemistry, Washington and Jefferson College, Washington, Pennsylvania 15301, United States.Department of Chemistry, Physics, & Engineering, Franciscan University, Steubenville, Ohio 43952, United States.Department of Chemistry & Biochemistry, Center for Computational Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, United States.Department of Chemistry, Marshall University, Huntington, West Virginia 25755, United States.Department of Chemistry & Biochemistry, Brigham Young University, Provo, Utah 84602, United States.Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.Department of Chemistry, Washington and Jefferson College, Washington, Pennsylvania 15301, United States.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

32233483

Citation

Holmes, Sean T., et al. "Chemical Shift Tensors of Cimetidine Form a Modeled With Density Functional Theory Calculations: Implications for NMR Crystallography." The Journal of Physical Chemistry. A, vol. 124, no. 16, 2020, pp. 3109-3119.
Holmes ST, Engl OG, Srnec MN, et al. Chemical Shift Tensors of Cimetidine Form A Modeled with Density Functional Theory Calculations: Implications for NMR Crystallography. J Phys Chem A. 2020;124(16):3109-3119.
Holmes, S. T., Engl, O. G., Srnec, M. N., Madura, J. D., Quiñones, R., Harper, J. K., Schurko, R. W., & Iuliucci, R. J. (2020). Chemical Shift Tensors of Cimetidine Form A Modeled with Density Functional Theory Calculations: Implications for NMR Crystallography. The Journal of Physical Chemistry. A, 124(16), 3109-3119. https://doi.org/10.1021/acs.jpca.0c00421
Holmes ST, et al. Chemical Shift Tensors of Cimetidine Form a Modeled With Density Functional Theory Calculations: Implications for NMR Crystallography. J Phys Chem A. 2020 Apr 23;124(16):3109-3119. PubMed PMID: 32233483.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Chemical Shift Tensors of Cimetidine Form A Modeled with Density Functional Theory Calculations: Implications for NMR Crystallography. AU - Holmes,Sean T, AU - Engl,Olivia G, AU - Srnec,Matthew N, AU - Madura,Jeffry D, AU - Quiñones,Rosalynn, AU - Harper,James K, AU - Schurko,Robert W, AU - Iuliucci,Robbie J, Y1 - 2020/04/14/ PY - 2020/4/3/pubmed PY - 2020/4/3/medline PY - 2020/4/3/entrez SP - 3109 EP - 3119 JF - The journal of physical chemistry. A JO - J Phys Chem A VL - 124 IS - 16 N2 - The principal components of the 13C chemical shift tensors for the ten crystallographically distinct carbon atoms of the active pharmaceutical ingredient cimetidine Form A have been measured using the FIREMAT technique. Density functional theory (DFT) calculations of 13C and 15N magnetic shielding tensors are used to assign the 13C and 15N peaks. DFT calculations were performed on cimetidine and a training set of organic crystals using both plane-wave and cluster-based approaches. The former set of calculations allowed several structural refinement strategies to be employed, including calculations utilizing a dispersion-corrected force field that was parametrized using 13C and 15N magnetic shielding tensors. The latter set of calculations featured the use of resource-intensive hybrid-DFT methods for the calculation of magnetic shielding tensors. Calculations on structures refined using the new force-field correction result in improved values of 15N magnetic shielding tensors (as gauged by agreement with experimental chemical shift tensors), although little improvement is seen in the prediction of 13C shielding tensors. Calculations of 13C and 15N magnetic shielding tensors using hybrid functionals show better agreement with experimental values in comparison to those using GGA functionals, independent of the method of structural refinement; the shielding of carbon atoms bonded to nitrogen are especially improved using hybrid DFT methods. SN - 1520-5215 UR - https://www.unboundmedicine.com/medline/citation/32233483/Chemical_Shift_Tensors_of_Cimetidine_Form_A_Modeled_with_Density_Functional_Theory_Calculations:_Implications_for_NMR_Crystallography L2 - https://doi.org/10.1021/acs.jpca.0c00421 DB - PRIME DP - Unbound Medicine ER -
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