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Synthesis, characterization, spectroscopic and antioxidation studies of Cu(II)–morin complex

“…The co-ordination site and binding properties of the ligand are discussed on the basis of spectroscopic analysis. The IR spectra of the ligand and complex were recorded in the 4000-400 cm À1 region and are not similar [24]. The comparison of both spectra reveals the important spectral changes, notably; the characteristic band of carbonyl group t(C@O) in the morin appears at 1662 cm À1 , while in the complex it appears at 1650 cm À1 .…”

Synthesis and Characterization of Nanosized Uranyl Coordination Polymers Derived from Terephthalic Acid and Azoles

“…Furthermore, the stretching vibration of the amino group in free ABZ observed at 3220 cm -1 is shifted to a lower wave number and . The bands at 3410-3440 cm -1 in the spectra of the complexes are assigned to íOH of the crystalline water molecules 24,25 . Metal-oxygen and metal-nitrogen bonding are manifested by the appearance of bands in the 520-536 cm -1 and 410-440 cm -1 regions respectively 26 .…”

1H NMR and spectroscopic studies of biologically active yttrium (III)-flavonoid complexes

“…There are only two absorption bands observed in the spectrum of L1 and L2 in methanol and DMF solutions ( Figures 2 and 3) [16,[27][28][29]. Two peaks at 412 (I) and 238 nm(II) in methanol, 375(I) and 262 nm (II) in DMF; at 403(I) and 236(II) in methanol, at 411(I) and 244 nm(II) in DMF are observed in the spectrum of free L1 and L2, respectively [19][20][21][22]. The observed absorption band at higher wavelength (lower frequency) is assigned to the p-p and n-p transitions, and a second band observed at lower wavelength (higher frequency) is due to Main Group Chemistry 135 the p-p and n-s transitions, that correspond to ring A (quinolic system) and ring B (catechol system), respectively [28,29].…”

“…Some flavonoids possess strong antioxidant activity through their ability to scavenge free radicals and chelate metal ions [15][16][17][18][19][20]. The chelating capacities of flavonoids with metal ions such as transition and non-transition metals have been reported earlier and demonstrated that their coordination complexes were better inhibitors of free radicals than the ligands alone [17][18][19][20]21]. As a result of their potential utility in biomedical science flavonoid coordination chemistry has been extensively studied [15][16][17][18][19][20][21][22][23][24][25].…”