Table 1.

Experimental mid-IR band positions recorded for ${\text{C}}_{17}{\text{H}}_{11}^{+}$ and calculated positions for ${\text{PyrCH}}_2^{+}$ and ${\text{PyrC}}_7^{+}$ isomers (see Figure 2) obtained in the present work. The intensities corresponding to the maximum of the convoluted spectra are also reported.

Experiment		Calculations
ν (cm–1)	ν (cm–1)	ν (cm–1)	Inten. (km · mol–1)
IR-PD	IRMPD	DFT-B3LYP
${\text{PyrCH}}_2^{+}$
1240(25)	1223(21)	1236	117
1376(9)	1362(23)	1376	144
1529(12)	–	1535	92
1570(21)	1568(26)	1574	154
1615(16)	–	1615*	407
${\text{PyrC}}_7^{+}$
–	–	1212	148
–	–	1496	274

Note: Consult SI for the visualisation of modes.

^*– mode used to determine the scaling factor.