Proton magnetic shielding studies of pure, gaseous hydrogen bromide

摘要: An experimental investigation of the temperature dependence proton chemical shift δ pure, gaseous hydrogen bromide as a function density p and has been carried out. At any given over range studied (−20°C–C-+60°C) is linearly dependent on density. Thus, = δ0 + (gσ1/Vm) where at zero density, Vm molar volume, δ1 determined by bulk susceptibility effect intermolecular interactions between pairs molecules. The values σ0 σ1 are both temperature-dependent. The yields information concerning parameters σe(i) in ‘proton shielding function’ σ(ξ) σe(0) σe1 ξ 12σ(2) ξ2 …, relative internuclear displacement. results σe(1) −564(±37) ppm 0.00172σe(2) 42.18(±0.47) ppm. isotope σ(H81Br)−σ(H79Br) HBr calculated to be 0.001 very large not adequately explained current theories.