Parametrizing the spatial dependence of 1H NMR chemical shifts in .pi.-stacked molecular fragments

0533631 - ÚMCH 2021 RIV CH eng J - Journal Article
Czernek, Jiří - Brus, Jiří
Parametrizing the spatial dependence of 1H NMR chemical shifts in .pi.-stacked molecular fragments.
International Journal of Molecular Sciences. Roč. 21, č. 21 (2020), s. 1-13, č. článku 7908. E-ISSN 1422-0067
R&D Projects: GA MŠMT(CZ) LTAUSA18011
Research Infrastructure: e-INFRA CZ - 90140
Institutional support: RVO:61389013
Keywords : noncovalent interactions * proton NMR * intermolecular stacking
OECD category: Physical chemistry
Impact factor: 5.924, year: 2020
Method of publishing: Open access
https://www.mdpi.com/1422-0067/21/21/7908

Most recently a renewed interest in several areas has arisen in factors governing the 1H NMR chemical shift (1H CS) of protons in aromatic systems. Therefore, it is important to describe how 1H CS values are affected by π-stacking intermolecular interactions. The parametrization of radial and angular dependences of the 1H CS is proposed, which is based on conventional gauge-independent atomic orbital (GIAO) calculations of explicit molecular fragments. Such a parametrization is exemplified for a benzene dimer with intermonomer vertical and horizontal distances which are in the range of values often found in crystals of organic compounds. Results obtained by the GIAO calculations combined with B3LYP and MP2 methods were compared, and revealed qualitatively the same trends in the 1H CS data. The parametrization was found to be quantitatively correct for the T-shaped benzene dimers, and its limitations were discussed. Parametrized 1H CS surfaces should become useful for providing additional restraints in the search of site-specific information through an analysis of structurally induced 1H CS changes.
Permanent Link: http://hdl.handle.net/11104/0312402