STRUCTURE AND QUADRUPOLE COUPLING MEASUREMENTS ON CIF3

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, r Cl-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. © 1990 American Institute of Physics.