6533b7d0fe1ef96bd125b899
RESEARCH PRODUCT
Understanding the ring current effects on magnetic shielding of hydrogen and carbon nuclei in naphthalene and anthracene
Inmaculada García CuestaAlfredo Sánchez De MerásStefano PelloniPaolo Lazzerettisubject
AnthraceneHydrogennaphthalenechemistry.chemical_elementGeneral ChemistryAromatic ring currentMagnetic fieldComputational Mathematicschemistry.chemical_compoundchemistrycurrent density mapsElectromagnetic shieldingproton and carbon chemical shiftAtomic physicsnaphthalene; ring currents; proton and carbon chemical shift; current density mapsCarbonCurrent densityring currentsRing currentdescription
The local response to an external magnetic field normal to the molecular plane of naphthalene and anthracene was investigated via current density and magnetic shielding density maps. The Biot-Savart law shows that the deshielding caused by pi-ring currents in naphthalene is stronger for alpha- than for beta-protons due to geometrical factors. The shielding tensor of the carbon nuclei in both molecules is strongly anisotropic and its out-of-plane component determines the up-field chemical shift of (13)C in nuclear magnetic resonance spectra. The pi-ring currents flowing beyond the C-skeleton in front of a probe carbon nucleus, and on remote parts of the molecular perimeter, yield positive contributions to the out-of-plane component of carbon shielding as big as approximately 10-15% of the total values. Near Hartree-Fock estimates of magnetizability and magnetic shielding at the nuclei fully consistent with the current model are reported.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2008-08-20 | Journal of Computational Chemistry |