Electric dipole moment of IBr by the Stark shift of the perturbation allowed rotational transition J'=3 - J''=0

The perturbation allowed rotational transition J'=3 - J''=0 was pumped with a high power klystron and the resonance was detected with the allowed transition J'=3 - J''=3 by a double resonance method. The Stark effect of the 3 - 0 transition is mainly determined by the Stark shift of the J''=0 state. From the observed Stark splitting of several hyperfine components of this transition in the ground vibrational state the electric dipole moment was derived: mod(μ0)=0.737(10) debye. An empirical diagram is given for the electric dipole moments of the diatomic interhalides as a function of the internuclear distance. (Auth.)