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

Table 5

Electronic spectra, magnetic moments, and molar conductivity data of Schiff bases and their metal complexes.

Symbol	Band positions (cm^−1)	Assignment	𝜇eff (B.M)	Molar conductivity; S·mol^−1·cm^2 in DMF
EDH4	33222, 24691	π → π*	—	0.0018
PDH4	33222, 27777	π → π*	—	0.011
	20833	𝑛 → π*
MPDH4	33333	π → π*	—	0.0007
	27777	𝑛 → π*
C1	32362, 29154	Intraligand π → π*	0.386 oh	0.022
	23255	C.T
	15431	^2B1g → ^2B2g
	13513	^2B1g → ^2A1g
C2	33444	Intraligand π → π*	0.514 oh	0.251
	26315	C.T
	18868	^2B1g → ^2B2g
C3	33333	Intraligand π → π*	1.260 Sq.	0.093
	25641	C.T
	15625	^2B1g → ^2B2g
	12658	^2B1g → ^2A1g
C4	37735, 34843	Intraligand π → π*	1.023 oh	0.046
	27247	C.T
	23148	^2B1g → ^2Eg
	10989	^2B1g → ^2A1g
C5	34013, 27247	Intraligand π → π*	1.061 Sq.	149
	23313	C.T
	16025	^2B1g → ^2B2g
C6	34129, 28571	Intraligand π → π*	0.810 oh	0.114
	25974	C.T
	22883	^2B1g → ^2Eg
	10460	^2B1g → ^2A1g
C7	36363, 33333	Intraligand π → π*	2.440 oh	0.043
	31250
	26178	C.T
	15731	^4T1g → ^4T1g (P)
	10504	^4T1g → ^4A2g
	7083 cal.	^4T1g → ^4T2g
C8	34843, 33003	Intraligand π → π*	0.200 oh	0.273
	28248	C.T
	15983.	^4T1g → ^4T1g (P)
	9900	^4T1g → ^4A2g
	6456 cal.	^4T1g → ^4T2g
C9	36363, 27247	Intraligand π → π*	1.092 Sq.	0.0002
	23310	C.T
	19920	^2B1g → ^2Eg
	15313	^2B1g → ^2B2g
	10298	^2B1g → ^2A1g
C11	29585	Intraligand π → π*	2.017 Sq.	0.005
	26041	C.T
	21739	^2B1g → ^2Eg
	15873	^2B1g → ^2B2g
C12	36496, 32894	Intraligand π → π*	1.023 oh	0.013
	27624	C.T
	22935	^2B1g → ^2Eg
	10482	^2B1g → ^2A1g
C13	33333, 29239	Intraligand π → π*	0.440	163
	27027	C.T
	22472	^2B1g → ^2Eg
C14	34013, 29154	Intraligand π → π*	1.89 Sq.	158
	27027	C.T
	18833.	^2B1g → ^2B2g
C15	29325	Intraligand π → π*	1.783 oh	0.023
	27397	C.T
	22727	^2B1g → ^2Eg