Table 2.

Gas‐phase IR data for HP¹²CO and DP¹²CO.

vibration	assignment	HPCO	HPCO calc.39	DPCO	DPCO calc.39
ν1	νPH [a]	2306	2278	1620	1634
ν2	νCO	2011	2018	2012	2018
ν3	δHPC	873	891	–	761
ν4	νPC [a]	697	730	–	678
ν5	δPCO [b]	368	387	–	345
ν6	δPCO [c]	–	472	–	471
ν2 + ν4		2707	2663	–	2619
2 × ν4		1394	1411	–	1327
ν3 + ν5		1241	1225	–	1091
ν4 + ν5		1066	1081	–	1001

[a] Partially obscured by CO₂. [b] Determined from combination and overtone bands. [c] Not observed due to low IR activity. Calculated data scaled by 0.95.