The Fundamental Absorption Bands in the Infrared Spectrum of Phosphine

Abstract

The four fundamental bands in the infrared spectrum of PH₃ have been analyzed. The bands ν₁ and ν₃ yield values of B^(xx) and [(1—ζ₂^(z))B^(zz)—B ^(xx)] as well as values for the centers of the bands. The method of Nielsen for arriving at explicit expressions for the rotation term values of ν₂ and ν₄ has permitted the evaluation also of the quantity (1—ζ₄^(z))B^(zz) and to infer the centers of these bands. The structure of the molecule has been derived from this information and the zeta sums. The PH distance r₀ obtained is equal to 1.42A, and the H–P–H angle is equal to 93° 50′.