Combined FTIR Matrix Isolation and Density Functional Studies of Indole-3-Pyruvic Acid Molecule. Spectroscopic Evidence of Gas-Phase Tautomerism

Table 3

Summary of some characterizing modes of the molecule (B3LYP/6-311++G** unscaled values).

	δC–O–H	νC–O–H	(C–OH) tors	ν Cα–Cβ^(a)	δ ipNH	δ opNH
H01	1338	1114	557		1459	449
	1310	1172	508
K02	1375	1188	703	763	1447	412
K03	1384	1188	699	768	1446	403
K04	1355	1200	725	772	1448	398
K06	1373	1197	716	784	1450	403
K07	1370	1186	651	745	1445	429
K09	1372	1184	653	748	1447	417
H05	1326	1058	563		1454	449
	1143	1091	644

^(a)denotes the C_αC_β bond of the keto-carboxylic section of the K type species.