Table 4. Experimental, Calculated IR Frequency and Assignment for Molecule 4a.

IR experimental frequency (wavenumber cm–1)	IR calculated (B3LYP/6-31G*) (wavenumber cm–1)	assignment
519.65	527.86	ν C–H
632.55	642.54	ν C–H
706.39	718.36	ν N–H
802.65	807.04	ν C–H
904.65	947.40	ν C–H
1276.49	1274.85	ν C–H
1432.54	1422.39	ν C=N
1479.98	1496.53	ν C–H
1543.76	1566.16	ν C–N
1609.18	1599.23	ν C=C
1659.98	1636.42	ν C=C
1689.78	1717.16	ν C=O
1755.21	1798.15	ν C=O
3001.34	3213.37	ν C–H aromatic
3178.76	3220.99	ν C–H aromatic