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Table 4: Comparison of the observed IR of (PVK-PHT) copolymer and calculated (by DFT-B3LYP/3-21G* level) vibrational wavenumbers (cm−1) of (Cbz-Mth)3.

Exp. Freq. (cm‒1) I Calc. Freq. (cm‒1) I Assignments — — 537.2 w Ring bending $+$ wagging CH3 590 w 614.57 w Ring bending 632.8 w 719.8 m Both peaks are for C–H out of plane vibration 728.4 s 734.1 m Wagging rocking—of methylene in polyvinyl 768.5 w 811.5 w Out of plane deformation C–H 937.9 m 930.5 w Aromatic out of plane C–H bending $+$ aliphatic C–H rocking 1023.6 w — — ν(C–S) ring (thiophene) 1089.1 vs 1030.1 w ν(C–H) stretching vibration 1132 m 1098.8 m ν(C–N) Carbazole 1180 m 1212.8 m Stretching vibration ν(C–S) thiophene 1331.9 m 1312.2 m C–H bending of vinyl group 1400.6 m 1358.6 m Ring vibration of PVK moiety — — 1403.6 s Stretching N–H + deformation and rocking C–H + wagging CH3 + deformation CH3 1458.4 s 1431.5 s Ring vibration of PVK moiety 1598.8 m 1529.9 m Aromatic C–C stretching 1628.3 w 1621.6 vs Asymmetric deformation ${\delta }_{\text{as}}$(N–H) and ν(C=C) ring in the Thiophene — — 1776.4 vs In plane C=C aromatic stretching — — 1868.1 s C–C inter-ring stretching 2850 w 3190.4 w Stretching of (C–N) group, aromatic ring of Carbazole 3400.3 m 3326.8 w Aromatic C–H stretching (terminal group)

vs: very strong; s: strong; m: mean; w: weak; vw: very weak.