Journal of Spectroscopy

Research Article

Structural and Vibrational Study on Monomer and Dimer Forms and Water Clusters of Acetazolamide

Table 3

Experimental FT-IR (solid and aqueous solution) and Raman and calculated wavenumbes (cm⁻¹) of the global conformations of monomeric, dimeric, and H₂O clusters (VI and X) forms of acetazolamide molecule.


Assignment		This work					This work calculated by DFT/6-31++G(d,p)							PED (5%) Free acetazolamide
This work	[13]	Experimental			Experimental		Free			Cluster VI	Cluster X	Dimer I
This work	[13]			Raman		Raman			Raman Int. Mono				Raman Int. Dimer I

(N–H)	N–H	3339 vs	—	3337 vw	3331 m^a; 3301 s^b	—	3473	3637	631	3474	3433	3484; 3484	1169; 22	(100)
(N–H)	N–H	3234 s	3193	3225 m	3227 m^a; 3179 m^b	3230 w^a; 3183 sh^b	3451	3614	1980	3221	3099	3035; 2995	28; 4931	(100)
(N–H)	N–H	3151 s	—	3145 w	3148 m^a; 3093 w^b	3152 w^a; 3089 s^b	3361	3520	1690	3360	3334	3364; 3364	119; 3162	(100)
(CH₃)	CH₃	3004 s	—	—	3001 vw^a; 3014 vw^b	3014^b	3007	3149	1564	3011	3018	3015; 3014	181; 26336	(100)
(CH₃)	CH₃	2948 m	—	2979 sh	2916 w^a; 2985 vw^b	2941 vs^a; 2985^b	2996	3138	1759	2995	2982	2992; 2992	3199; 575	(99)
(CH₃)	CH₃	2923 m	—	2933 vs	2932^b	2932^b	2924	3061	5191	2924	2914	2923; 2923	7119; 3177	(100)
(C=O)	C=O	1699 vs	1694	1707 s	1698 s^a; 1680 s^b	1708 m^a; 1677 w^b	1724	1765	3123	1720	1719	1721; 1720	45; 5313	(77) + (6) + (7)
NH_2(scis,)	NH_ip	1558 sh	1569	—	1574 w^b	1571^b	1562	1599	173	1560	1619	1554; 1554	200; 145	(96)
(C=N) +	C=N_ring	1550 vs	1552 s	1555 m	1542 vs^a; 1553 vs^b	1558^b	1519	1554	6783	1546	1575	1581; 1565	2005; 15	(60) + (28)
(CH₃)	—	1457 w	1457	—	1454 sh^b	1455 sh^b	1460	1494	749	1459	1479	1463; 1462	72; 1099	(74) + (13)
(CH₃)	C=N + CH₃	1437 s	1435	1442 vs	1436 m^a; 1437 m^b	1443 vs^a; 1434 m^b	1440	1474	932	1443	1451	1449; 1448	611; 204	(81) + (8) + (8)
ν _as(C=N)_ring	C=N CH₃	1420 sh	1418	1428 sh	1426 sh^b	1422^b	1442	1476	2472	1449	1443	1456; 1456	7540; 1329	(77) + (6)
(C=N)_ring	CH₃	1384 sh	1387	1370 w	1376 sh^b	1386^b	1409	1442	5198	1424	1428	1439; 1435	72; 16412	(54) + (23) + (6)
(CH₃)	SO₂	1365 s	1363	—	1368 vs^b	1373^b	1376	1409	1144	1377	1388	1379; 1379	1312; 42	(92) + (6)
ν _as(SO₂)	C–N–C	1346 vs	1344	1347 m	1343 vs^a; 1322 s^b	1348^a	1312	1343	750	1314	1296	1319; 1319	1226; 690	(90) + (6)
(C–N)	C–N_ring	1282 s	—	1308 w	1280 m^a, 1286 m^b	1242 w^a, 1289^a	1291	1322	109	1299	1249	1300; 1298	11; 186	(62) + (13) + (7) + (5)
	—	1234 s	1234	1241 m	1227 s^a		1197	1225	629	1223	1319	1232; 1226	2041; 15	(29) + (19) + (13) + (12) + (9)
(SO₂) + (N–N)_ring	SO₂	1168 vs	1166	1165 s	1163 vs^a; 1176 vs^b	1167 s^a, 1168^b	1121	1147	1022	1133	1100	1134; 1132	186; 1905	(59) + (34)
(SO₂) + (N–N)_ring	CNNC	1105 m	1106	1103 sh	1122 m^b	1121^b	1100	1126	5630	1104	1140	1105; 1104	10516; 439	(42) + (39)
(NH₂)	“Ring mode”	1096 s	1097	1094 s	1095 s^a; 1087 m^b	1097s^a; 1085m^b	1071	1096	323	1070	1171	1063; 1063	14; 778	(91)
	“Ring mode”	1038 w	1038	—	1045 m^a, 1045 m^b	1041^b	1042	1066	538	1045	1048	1046; 1045	139; 1528	(44) + (42)
(CH₃)	—	—	—	—	1011^a, 1014^b	1016^b	1031	1055	10	1033	1045	1036; 1036	9; 29	(72) + (10) + (16)
(CH₃)	N–N	996 m	995	998 w	975 m^b	955 m^a, 968^b	993	1016	276	1000	1014	1009; 1007	198; 1	(55) + (18)
(C–N) + (C–C)	S–N	944 s	947	956 m	939 s^a, 913 m^b	916^b	949	971	854	954	963	953; 949	2; 2584	(25) + (18) + (9) + (15) + (8) + (7) + (6)
(S–N)	“Ring mode”	813 m		807 vw	813 w^a, 844 w^b	—	824	843	2623	821	829	817; 817	573; 6259	(55) + (15)
	“Ring mode”	783 m		—	780 m^a, 817 m^b	821^b	786	805	24	792	793	798; 786	9; 201	(17) + (7) + (12) + (42)
(C–S)_ring	(C–S)_ring	705 m	719	709 s	705 w^a; 710 w^b	712 m^a; 711^b	672	688	1385	681	682	683; 681	3652; 11	(58) + (9) + (9) + (12)
w(NH₂)	(C–S)_ring	675 s	668	680 vs	674 s^a, 673 s^b	684 vs^a, 680^b	668	684	408	667	988	626; 624	5395; 178	(36) + (19) + (16) + (13)
(C–S)_ring +	—	644 m	643	647 sh	643^a; 651 w^b	645^b	645	660	5062	648	661	661; 659	8007; 3	(23) + (23) + (16) + (6) + (6)
	N–C=O	621 vs	618	637 w	620 s^a, 622 s^b	636 w^a, 624^b	624	639	225	639	636	635; 635	225; 69	(44) + (30) + (11)
	—	608 sh		610 vw	613^b	607^b	608	622	16	778	591	597; 595	89; 52	(24) + (16) + (20)+ (13) + (11) + (8) + (7)
	SO₂	582 m		580 w	584 m^b	588^b	588	602	65	593	575	578; 576	123; 36	(50) + (10) + (21) + (6)
(C–C=O)		573 m	575	—	574 m^b	578 m^a, 574^b	573	586	392	576	611	573; 570	28; 565	(19) + (10) + (16) + (8) + (7) + (5)
w(SO₂) + w(NH₂)	O=C–C	—		—	554 m^b	560^b	535	547	279	535	524	532; 531	106; 670	(34) + (10) + (10) + (12) + (5)
(N–H)	—	508 s	881	507 w	520 s^b	507^b	531	544	97	778	878	881; 864	3; 47	(25) + (20) + (16) + (10) + (8)
(SO₂)	wag SO₂	457 vw	545	453 w	458 m^b	450 w^a, 453^b	467	478	1731	469	514	470; 470	702; 1107	(40) + (25) + (11) + (5)
(SO₂) + t(NH₂)	SO₂	406 vw		413 w	411 w^b	417 w^a, 406^b	432	442	208	435	468	433; 433	559; 16	(48) + (16) + (7) + (7) + (7)
t(NH₂) + t(SO₂)	—	—		—	398^b	395 sh^b	393	403	245	406	440	400; 400	35; 1655	(51) + (18) + (9)
	Latice vib.	—		373 w	—	374 m^a, 368^b	386	395	1489	388	404	386; 384	2455; 190	(21) + (18) + (16) + (7) + (13) + (7) + (6)
	—	—		326 w	—	328 w^a, 330^b	346	354	298	353	364	360; 355	15; 364	(41) + (23) + (5)
t(NH₂)	—	—		267 m	—	270 s^a, 270^b	291	298	503	302	386	316; 315	34; 594	(19) + (19) + (19) + (6)
t(NH₂)	—	—		253 sh	—	256 m^a, 258^b	274	280	363	274	—	275; 275	12; 952	(23) + (17) + (9) + (8) + (9)
	—	—		—	—	230^b	235	241	4727	237	270	237; 233	5884; 325	(42) + (25) + (13) + (6)
	—	—		195 w	—	192^b	219	224	291	230	231	243; 241	4402; 112	(32) + (32) + (18)
	—	—		160 w	—	136^b	163	166	425	176	197	165; 163	1835; 12	(55) + (29)
	—	—		116	—	118^b	123	126	1587	127	133	138; 132	4227; 114	(33) + (27) + (15) + (10)
	—	—		105	—	105^b	90	92	887	87	130	102; 100	567; 764	(44) + (13) + (14)
	—	—		—	—	—	88	90	295	98	104	118; 104	57; 25	(54) + (9) + (7) + (6)
t(CH₃)	—	—		—	—	—	56	57	1122	50	116	78; 62	817; 1641	(36) + (18) + (10) + (6) + (6)
t(CH₃)	—	—		—	—	—	39	40	2415	43	106	51; 48	459; 3691	(69) + (17) + (6)
	—	—		—	—	—	11	11	1622	21	13	31; 12	572; 4369	(65) + (15)

Ref [13], ^bRef [24].