Preparation and Characterization of Di-, Tri-, and Tetranuclear Schiff Base Complexes Derived from Diamines and 3,4-Dihydroxybenzaldehyde

Table 2

Significant bands in the FTIR spectra (cm⁻¹) for Schiff bases and their metal complexes.

Symbol	𝜈OH	𝜈C−H	𝜈C=N imine	𝜈C=N bipy.	𝜈ClO4 ionic (Coord.)	𝜈 H2O lattice (Coord.)	𝜈M−O	𝜈M−N	𝜈M−Cl
EDH4	3263	2839	1651	—	—	—	—	—	—
			1608
PDH4·4H2O	3253	2750	1631	—	—	3448–3417	—	—	—
			1604
MPDH4·MeOH	3251	2985	1670	—	—	—	—	—	—
C1	—	2860	1654	1519	—	(3150, 767, 651)	420	370	—
		2760	1608
C2	—	2950	1640	1500	—	3400 (3250, 775, 660)	460	350	—
			1610
C3	—	2900	1658	1570	—	3444	474	385	297^a
			1604						254^b
C4	—	2800	1643	1543	—	(3356, 771, 729)	470	385	340^a
		2750	1604
C5	—	2819	1651	1570	1111, 1083, 1037	—	470	333	—
		2746	1608
C6	—	2950	1660	1570	(1093, 1040)	3580 (3240, 750, 675)	550	341	—
		2800	1610
C7	—	2750	1653	1580	—	3750 (3300, 770, 650)	490	405	312^a
			1610						241^b
C8	—	2980	1640	1560	—	(3240, 775, 655)	560	395	325^a
		2870	1610						270^b
C9	—	2951	1655	1573	—	—	478	358	—
		2839
C10	—	2980	1630	1590	—	3550	490	400	—
C11	—	2823	1651	1570	—	3456	489	389	—
		2754	1608
C12	—	2950	1645	1550	—	3700 (3250, 690, 640)	450	322	304^a
		2800	1600						250^b
C13	—	2960	1660	1550	—	(3300, 770, 640)	560	343
		2850	1610
C14	—	2750	1639	1570	1103, 1050	—	459	393
			1604
C15	—	2800	1620	1550	(1091, 1050)	3600 (3380, 771, 740)	510	400

aTerminal; bbridged.