title: NMR shielding constants in PH3, absolute shielding scale, and the nuclear magnetic moment of 31P.
abstract: Ab initio values of the absolute shielding constants of phosphorus and hydrogen in PH(3) were determined, and their accuracy is discussed. In particular, we analyzed the relativistic corrections to nuclear magnetic resonance (NMR) shielding constants, comparing the constants computed using the four-component Dirac-Hartree-Fock approach, the four-component density functional theory (DFT), and the Breit-Pauli perturbation theory (BPPT) with nonrelativistic Hartree-Fock or DFT reference functions. For the equilibrium geometry, we obtained σ(P) = 624.309 ppm and σ(H) = 29.761 ppm. Resonance frequencies of both nuclei were measured in gas-phase NMR experiments, and the results were extrapolated to zero density to provide the frequency ratio for an isolated PH(3) molecule. This ratio, together with the computed shielding constants, was used to determine a new value of the nuclear magnetic dipole moment of (31)P: μ(P) = 1.1309246(50) μ(N).
authors.affiliation: Department of Physics, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland.
authors.forename: Perttu
authors.initials: P
authors.lastname: Lantto
authors.forename: Karol
authors.initials: K
authors.lastname: Jackowski
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Makulski
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Olejniczak
authors.forename: Michał
authors.initials: M
authors.lastname: Jaszuński
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D010720:Phosphines / Q000737:chemistry*; D010759:Phosphorus Isotopes; D011789:Quantum Theory
chemical_list: D010720:Phosphines; D010759:Phosphorus Isotopes