The ν3 fundamental band of HCNH + and the 2 ν3 ← ν3 and ν2 + ν3 ← ν2 hot bands of HCO +

Abstract

The ν 3 (CN stretch) fundamental band of HCNH + and the 2 ν 3 ← ν 3, ν 2 + ν 3 ← ν 2 hot bands of HCO + have been observed in the 5-μm region using a tunable infrared diode laser and an ac glow discharge. We have combined these transitions with previously observed transitions and determined the following molecular constants: HCNH +, B e = 37 275,4(7) MHz and α 3 = 192.4(3) MHz; HCO +, χ 23 = 0.134(2) cm −1 and χ 33 = −10.054(2) cm −1. We also calculated B e's of HCNH + isotopic species by scaling α i from the theoretical prediction and estimated the equilibrium bond-length of HCNH +.