Structure and quadrupole coupling measurements on ClF3

Abstract

Seventy-nine new microwave transitions for 35ClF3 and 37ClF3 in the 6–18 GHz range were measured using a Flygare–Balle-type spectrometer. Rotational transition frequencies were used to obtain ‘‘effective’’ structure parameters for the ground vibrational state zCl–F (along C2 axis)=1.5985(4) Å, rCl–F =1.700 73(5) Å and ΘF–Cl–F =87.48(4)°. Analysis of hyperfine structure due to chlorine quadrupole coupling and observed transition frequencies yield the following molecular parameters for 35ClF3: A=13 748.25(1) MHz, B=4611.719(2) MHz, C=3448.629(3) MHz, eQqaa=82.03(3) MHz, and eQqbb=65.35(2) MHz. Molecular parameters obtained for 37ClF3 are: A=13 653.54(1) MHz, B=4611.866(2) MHz, C=3442.719(4) MHz, eQqaa=64.66(4) MHz, and eQqbb=51.53(3) MHz.