Hyperfine Structure in thel-Type Doubling Spectrum of HCN

Abstract

Direct $l$-type transitions for HCN have been observed for $J=1, 2, 3, 4, \mathrm{and} 5$. Values obtained of the asymmetry parameter $\eta =-0.082\mathrm{}\pm 0.005$ and the magnetic coupling constant $c_i=13\mathrm{}\pm 5$ kc/sec are in good agreement with previous work. For ${\mathrm{N}}^{14}$ the value $e{q}_{m}Q=-4.81\mathrm{}\pm 0.02$ Mc/sec is 5% higher than that obtained in the ground vibrational state. This change in $e{q}_{m}Q$ can be explained by a decrease in the hybridization of the $\sigma$ bond.