Deuterium Nuclear Quadrupole Interaction in FC≡CD, CH3C≡CD, and ClC≡CD

Abstract

The deuterium nuclear quadrupole coupling constants of CH₃–C≡C–D, Cl–C≡C–D, and F–C≡C–D have been determined in order to investigate the effect of substitution on the electron distribution in the C—D bond. The results along the C—D bond yield χ_D=208±10 kc/sec for CH₃–C≡C–D, χ_D=212±10 kc/sec for F–C≡C–D, and χ_D=225±18 kc/sec for Cl–C≡C–D. The results show equal deuteron field gradients within experimental error and therefore show that the C—D bond is relatively insensitive to the substitution at the other end of the acetylenic bond.