Stark effect measurements of molecular dipole moments

Abstract

Attention is drawn to the advantage of using certain selected a-type transitions of near-symmetric prolate asymmetric tops for precise determination of µ_b or µ_c in such molecules. For two such molecules, propynal and (E)-crotonaldehyde, new values of µ_b have been determined (Cm):

propynal µ_b = 4.897(50) × 10^-30

(E)-crotonaldehyde µ_b = 3.403(59) × 10^-30

which are substantially different from those previously published. Some other uses of Stark-effect measurements on such selected transitions are briefly indicated.