Table 1.

Experimental Raman (crystalline powder) spectral data of curcumin in frequency region 1700–900 cm⁻¹

Peak assignment	ν	ν	ν	ν	ν	ν	νCur	νCur	νCur	ν	ν	νCal.
	Cur N1	Cur N2	Cur N3	Cur N3-1 6 months later	Cur N4	N6	N8	N9	N10	Mangolim et al. (2014)	Kolev et al. (2005)	Kolev et al. (2005)
ν C=O (II)		1637			1636					1638
ν C=O (III)										1639
ν C=O (I) νC=C	1632		1627	1625		1632	1625	1626	1625	1626	1626	1630
ν C=C (I, II) Aromatic	1599	1599	1599	1599	1598	1599	1599	1600	1599	1600 1602	1601	1615
νC=C (II, III) Aromatic		1590	1579	1579						1591 1591		1587
ν C=O	1523	1536	1516	1523	1524	1536	1531	1533	1529		1509	1536
Phenol C–O (I)	1428		1435			1428	1429	1427	1428	1430	1431	1420
Phenol C–O (II, III)	1413	1413		1413	1413	1413				1416 1415		1409
Enol C–O (I)	1248	1248			1248	1248	1248	1247	1247	1249	1230	1216
Enol C–O (II, III)	1226	1229	1234	1226	1226	1226				1233 1234		1212
			1196				1205	1205	1205		1207	1196
	1183	1183	1168	1183	1183	1187	1181	1182	1182		1184	1176
	1166	1166		1166	1166	1161					1168	1169
	1148	1148		1148	1148		1150	1149	1149			1150
	1118	1118	1120	1118	1118	1128					1120	1107
ν C=O	962.6	971	976	975	975	981	959	961	961		967	966

Vibrational modes: ν stretching