Boron Trifluoride: The Analysis of ν2 and the Determination of the Molecular Geometry

Abstract

The parallel band ν 2 of 10BF3 has been remeasured with a resolution of about 0.03 cm−1 and new values of the rotational constants have been determined. The values of B 0 = 0.3447 4 ± 0.0005 ( 10 BF 3 ) and B 0 = 0.3450 5 ± 0.0005 cm −1 ( 11 BF 3 ) are consistent with the geometry obtained in the electron‐diffraction experiments of Kuchitsu and Konaka, but differ appreciably from the values previously reported by Nielsen. From our results we obtain r 0 = 1.309 6 ± 0.001 Å ( 10 BF 3 ) , r e = 1.309 0 ± 0.001 Å ( 11 BF 3 ) , and r 0 = 1.307 2 ± 0.002 Å ( 10 BF 3 ) . From the analysis of the hot bands we have determined values of (B ′ − B ″ ) for ν 4 and some of the anharmonic constants x ss ′ .