Spatial Contributions to Nuclear Magnetic Shieldings

Jinger, Rahul Kumar; Fliegl, Heike 1; Bast, Radovan; Dimitrova, Maria; Lehtola, Susi; Sundholm, Dage
1 Institut für Nanotechnologie (INT), Karlsruher Institut für Technologie (KIT)

Abstract:
We develop a methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities which are calculated from the current density via the Biot–Savart relation. Atomic contributions to nuclear magnetic shielding constants can be estimated within our framework with a Becke partitioning scheme. The new features have been implemented in the GIMIC program and are applied in this work to the study of the $^{1}H$ and $^{13}C$ nuclear magnetic shieldings in benzene ($C_{6}H_{6}$) and cyclobutadiene ($C_{4}H_{4}$). The new methodology allows a visual inspection of the spatial origins of the positive (shielding) and negative (deshielding) contributions to the nuclear magnetic shielding constant of a single nucleus, something which has not been hitherto easily accomplished. Analysis of the shielding densities shows that diatropic and paratropic current-density fluxes yield both shielding and deshielding contributions, as the shielding or deshielding is determined by the direction of the current-density flux with respect to the studied nucleus instead of the tropicity. Becke partitioning of the magnetic shieldings shows that the magnetic shielding contributions mainly originate from the studied atom and its nearest neighbors, confirming the localized character of nuclear magnetic shieldings.

 Zugehörige Institution(en) am KIT Institut für Nanotechnologie (INT) Publikationstyp Zeitschriftenaufsatz Publikationsdatum 04.03.2021 Sprache Englisch Identifikator ISSN: 1089-5639, 1520-5215 KITopen-ID: 1000135341 HGF-Programm 43.31.01 (POF IV, LK 01) Multifunctionality Molecular Design & Material Architecture Erschienen in The journal of physical chemistry / A Verlag American Chemical Society (ACS) Band 125 Heft 8 Seiten 1778–1786 Vorab online veröffentlicht am 19.02.2021 Nachgewiesen in Web of ScienceDimensionsScopus
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