PR AND QQ SEPARATIONS OF BAND ENVELOPES PRODUCED BY OBLATE ASYMMETRICAL TOP MOLECULES

Analysis of the observed QQ separations of band envelopes produced by a number of oblate asymmetrical top molecules, has shown that: Δν(QQ) = 1 3p*SB √2 cm-1 for molecules with 1 3 < ρ* ≤ 1 2 Δν(QQ) = 2 3p*SB √2 cm-1 for compounds with p* >/ 1 2SB refers to the predicted PR separation of the corresponding type B(⊥) band. Agreement between the calculated and observed QQ separations of the other asymmetrical top molecules was considered satisfactory. These formulas are therefore proposed as substitutes for the extrapolation technique usually applied to the curves of Badger and Zumwalt. Charts are included to permit a rapid estimation of the PR and QQ separations of type B(⊥) bands. © 1969.