title: Full four-component relativistic calculations of the one-bond 77Se-13C spin-spin coupling constants in the series of selenium heterocycles and their parent open-chain selenides.
abstract: Four-component relativistic calculations of (77)Se-(13)C spin-spin coupling constants have been performed in the series of selenium heterocycles and their parent open-chain selenides. It has been found that relativistic effects play an essential role in the selenium-carbon coupling mechanism and could result in a contribution of as much as 15-25% of the total values of the one-bond selenium-carbon spin-spin coupling constants. In the overall contribution of the relativistic effects to the total values of (1)J(Se,C), the scalar relativistic corrections (negative in sign) by far dominate over the spin-orbit ones (positive in sign), the latter being of less than 5%, as compared to the former (ca 20%). A combination of nonrelativistic second-order polarization propagator approach (CC2) with the four-component relativistic density functional theory scheme is recommended as a versatile tool for the calculation of (1)J(Se,C). Solvent effects in the values of (1)J(Se,C) calculated within the polarizable continuum model for the solvents with different dielectric constants (ε 2.2-78.4) are next to negligible decreasing negative (1)J(Se,C) in absolute value by only about 1 Hz. The use of the locally dense basis set approach applied herewith for the calculation of (77)Se-(13)C spin-spin coupling constants is fully justified resulting in a dramatic decrease in computational cost with only 0.1-0.2-Hz loss of accuracy.
authors.affiliation: A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033, Irkutsk, Russia.
authors.forename: Yury Yu
authors.initials: YY
authors.lastname: Rusakov
authors.forename: Irina L
authors.initials: IL
authors.lastname: Rusakova
authors.forename: Leonid B
authors.initials: LB
authors.lastname: Krivdin
mesh_terms: D006571:Heterocyclic Compounds / Q000737:chemistry*; D007554:Isotopes; D015394:Molecular Structure; D016566:Organoselenium Compounds / Q000737:chemistry*; D011789:Quantum Theory; D012643:Selenium / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D006571:Heterocyclic Compounds; D007554:Isotopes; D016566:Organoselenium Compounds; D012997:Solvents; D012643:Selenium
keywords: 77Se NMR; 77Se-13C spin-spin coupling constants; locally dense basis set; open-chain selenides; relativistic effects; scalar relativistic corrections; selenium heterocycles; solvent effects; spin-orbit relativistic corrections