Efficient Synthesis and Characterization of Some Novel Nitro-Schiff Bases and Their Complexes of Nickel(II) and Copper(II)

Table 3

Uv-Vis spectral data (DMF, nm) and IR bands (cm⁻¹) of ligands and their complexes.

Entry	𝑛→𝜋^∗ (C=N)	𝜋→𝜋^∗ (rings)	d → d	ν(C=N)	ν(Ph-O)	ν(O–H)	ν(NO2)	ν(M–N, M–O)
L1	409	284	—	1635	1330	3360	1532, 1338	—
L1[Cu(II)]	418	288	568	1608	1335	—	1530, 1341	460–490
L1[Ni(II)]	427	275	574	1615	1332	—	1539, 1347	465–492
L2	410	287	—	1643	1325	3353	1530, 1342
L2[Cu(II)]	429	280	570	1617	1338	—	1534, 1352	464–490
L2[Ni(II)]	430	271	571	1602	1339	—	1537, 1350	469–484
L3	407	291	—	1634	1324	3330	1534, 1329	—
L3[Cu(II)]	420	280	588	1603	1330	—	1541, 1323	451–480
L3[Ni(II)]	435	284	573	1609	1328	—	1551, 1319	455–487
L4	417	287	—	1641	1338	3382	1539, 1327	—
L4[Cu(II)]	427	279	582	1618	1324	—	1548, 1336	449–490
L4[Ni(II)]	432	283	574	1612	1329	—	1553, 1320	460–485
L5	416	295	—	1647	1321	3340	1527, 1355	—
L5[Cu(II)]	419	285	560	1615	1329	—	1529, 1353	458–494
L5[Ni(II)]	432	282	572	1600	1334	—	1527, 1349	462–481
L6	421	298	—	1642	1327	3294	1531, 1357	—
L6[Cu(II)]	428	284	561	1603	1338	—	1529, 1352	459–495
L6[Ni(II)]	430	279	570	1607	1336	—	1530, 1354	460–490
L7	410	289	—	1631	1319	3285	1538, 1340	—
L7[Cu(II)]	425	285	584	1615	1307	—	1541, 1348	465–498
L7[Ni(II)]	433	300	575	1620	1310	—	1530, 1339	458–487
L8	414	308	—	1645	1322	3354	1538, 1356	—
L8[Cu(II)]	426	302	587	1614	1335	—	1537, 1359	462–487
L8[Ni(II)]	431	294	568	1611	1331	—	1530, 1352	454–489