Solvent effects on the NMR parameters of H2S and HCN

✍ Scribed by Mikkelsen, Kurt V.; Ruud, Kenneth; Helgaker, Trygve

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 231 KB
• Volume: 20
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/(sici)1096-987x(199909)20:12<1281::aid-jcc8>3.0.co;2-c

✦ Synopsis

A recently developed method to calculate singlet and triplet gauge-origin᎐independent magnetic properties of solvated molecules is applied to the study of those parameters that determine an observed nuclear magnetic resonance signal: the magnetizability, the nuclear shieldings, and the indirect spin᎐spin coupling constants. The solvent is represented by a dielectric medium and the electronic structure of the solvated molecule by Hartree᎐Fock and multiconfigurational Hartree᎐Fock wave functions. For the properties that depend on the external magnetic field, we use London atomic orbitals to ensure gauge-origin independence and a rapid basis-set convergence. We find that the dielectric-medium effects on these molecules are substantial, being of the same order as rovibrational and electron correlation effects, and thus cannot be neglected if accurate comparisons with liquid-phase measurements are wanted. However, the present model is incapable of describing the close-range interactions that may occur in solution. It, therefore, represents the electrostatic effects of the bulk solvent, and the model is an initial approach towards a complete ab initio model for the study of magnetic properties of solvated molecules.