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

Table 1

Structural parameters of C₄H₄Se and C₄D₄Se^a.

Parameter^b	B3LYP/6-311G**		exp.^c
	𝑟𝑒	𝑟𝑧
Se–C1	1.876	1.883	1.863
C1=C2	1.360	1.365	1.370
C2–C3	1.432	1.438	1.423
C1–H	1.079	1.080	1.078
C2–H	1.083	1.086	1.081
C1–Se–C4	87.0	87.1	87.7
Se–C1=C2	111.5	111.4	111.2
C1=C2–C3	115.0	115.1	114.9
Se–C1–H	120.6	120.6	124.4
C1–C2–H	122.3	122.3	122.5
A	0.25234 (0.20745)	0.25044 (0.20609)
B	0.11171 (0.10174)	0.11113 (0.10123)
C	0.07743 (0.06826)	0.07694 (0.06786)
μ	0.378		0.4

aAll values refer to C₄H₄Se except for the perdeuterated isotopomer (values in parentheses).
^bBond lengths in Å, bond angles in degrees, rotational constants in cm⁻¹, and dipole moments in D.
^cMicrowave measurements [35].