Gas phase acidities and associated equilibrium isotope effects for selected main group mono- and polyhydrides, carbon acids, and oxyacids: A G4 and W1BD study

摘要: Abstract Gas phase standard state (298.15 K, 1 atm) enthalpies (Δ acid H ° (g) ) and free energies G of dissociation were calculated at the Gaussian-4 (G4) W1BD levels theory for a range perproteated, perdeuterated, pertritiated, partially isotopically labeled main group mono- polyhydrides, carbon acids, oxyacids. Excellent agreement was obtained between available experimental datasets theoretical estimates, with effectively equivalent Δ /Δ prediction accuracy G4 methods on acids The level provided errors about one-half those method hydrides. predicted primary secondary equilibrium isotope effects (EIEs) gas acidity deuterium tritium substitution exhibit periodic trends among hydrides, as well strength structure–property relationships some groups Primary EIEs various isotopologues 2 , LiH, CH 4 NH 3 SiH SH ClH hydrides using major isotopes each non-protic element declined in magnitude increasing atomic number due to decreasing mass differences respective isotopologues.