The electronic emission spectrum of triatomic hydrogen. III. Infrared perpendicular bands near 3600 cm−1

Abstract

The experimental techniques for obtaining spectra of triatomic hydrogen are described with special reference to studies in the infrared. An electronic transition near 3600 cm⁻¹ is observed in both H₃ and D₃. Its analysis shows that it is a ²A₁′–²E′ transition and that the upper state is identical with the upper state 3s²A₁′ of the 6025 Å band previously analysed (I. Dabrowski and G. Herzberg. Can. J. Phys. 58, 1238 (1980)) while the lower state is the upper state 3p²E′ of the 7100 Å band (G. Herzberg and J. K. G. Watson. Can. J. Phys. 58, 1250 (1980)). Improved constants are obtained for both these states from the infrared bands of H₃ and D₃. Perturbations in the upper state 3s²A₁′ of D₃ are clarified.