Infrared and Raman Spectra of C₄H₄Se and C₄D₄Se Isotopomers: A DFT-PT2 Anharmonic Study

Table 3

Vibrational harmonic, 𝜔, and anharmonic, 𝜈, wavenumbers (cm⁻¹), infrared intensities, 𝐼_IR (km/mol), and Raman activities 𝐴_Raman (Å⁴/amu) of C₄D₄Se.

		Description^a	B3LYP6-311G**				exp.^b
			𝐼IR	𝐴Raman	ω	ν	ν
A1	1	νC–D	1.4	115.3	2409	2334	2335
	2	νC–D	1.7	68.6	2360	2283	2280
	3	νC=C + νC–C + 𝛿C–D	21.4	40.4	1436	1403	1398
	4	νring + δC–D	4.9	6.8	1239	1215	1210
	5	Ring breathing + δC–D	1.0	19.7	863	849	847
	6	δC–D	1.0	4.9	788	781	774
	7	δring	16.4	7.6	691	682	683
	8	δC–Se–C	0.3	6.6	446	441	444
A2	9	𝛾C–D	0.0	0.8	766	757	748
	10	γC–D	0.0	0.0	532	527	528
	11	τring	0.0	0.0	473	469	475
B1	12	νC–D	0.3	0.1	2402	2335	2335
	13	νC–D	1.8	54.1	2344	2264	2267
	14	νC=C + δC–D	2.1	0.0	1506	1475	1460
	15	δC–D + νC–Se	8.9	0.4	1018	994	1001
	16	δring + δC–D	3.3	4.3	858	849	806
	17	δC–D	0.1	0.1	733	726	718
	18	νC–Se	1.4	4.8	588	578	592
B2	19	γC–D	0.2	0.2	694	687	690
	20	γC–D	74.9	0.1	525	522	520
	21	𝜏ring	0.5	1.1	366	363	362
		rms deviation^c			38	11
		rms deviation^d			22	12
		rms deviation^e			75	2

^a𝜈: stretching; 𝛿: in-plane bending, 𝛾: out-of-plane bending, 𝜏: torsion.
^bReferences [22, 23].
^cAll the vibrational modes.
^dAll the vibrational modes excluding the νC–H modes.
^eνC–H modes.