Spectral and structural studies of mono- and binuclear copper(II) complexes of salicylaldehyde N(4)-substituted thiosemicarbazones

Copper(II) complexes derived from di-2-pyridyl ketone-N4-phenyl-3-semicarbazone: Synthesis and spectral studies

“…This band is shifted to lower wavenumbers by 23-35 cm −1 in the spectra of complexes indicating coordination via the azomethine nitrogen [19][20][21]. Coordination of azomethine nitrogen is consistent with the presence of a band in the 504-511 cm −1 region, assignable to (Cu-N azomethine ) for these complexes [15,22]. But with loss of a proton from N, another strong band is found in the region 1599-1597 cm −1 which may be due to the newly formed C N bond due to enolization of the semicarbazone, which again confirms the coordination via enolate oxygen.…”

“…It is further corroborated with the appearance of a band in the 413-456 cm −1 region due to a (Cu-O) in the spectra of the complexes [16][17][18]. The (NH) band of the imino group is observed at 3369 cm −1 in the IR spectrum of HL and this band disappears in the spectra of the complexes, providing a strong evidence for the ligand coordination around copper(II) ion in the deprotonated form [15]. The intense band at 1591 cm −1 in the spectrum of HL has been assigned to (C N) of the semicarbazone moiety.…”

“…Mononuclear Cu(II) complexes 2, 4 and 5 exhibit magnetic moments in the range 1.76-2.04 B.M., which are close to the spin-only value [15]. Magnetic moments of binuclear Cu(II) complexes 1 and 3 lie in the range 1.36-1.47 B.M.…”

Design, synthesis and biological evaluation of thiosemicarbazones, hydrazinobenzothiazoles and arylhydrazones as anticancer agents with a potential to overcome multidrug resistance

“…In many cases not only free ligands, but also their metal complexes possess biological activity: picolinylidene TSC derivatives or their metal complexes have been reported to possess antimalarial [68], modest antibacterial [86], modest (to no) antifungal [87,88], but promising antitumor activity [88][89][90]. Salicylidene TSCs form redox-active complexes with various metal ions, including Ru(II) [91,92] and Cu(II) [93][94][95]. The free ligands and their Ni(II) [96], Cu(II), Ru(II) and Zn(II) [92,94,95] complexes were reported to possess antibacterial and antifungal activity.…”

(3,5-Dichlorosalicylaldehyde thiosemicarbazonato-κ3S,N1,O)(N,N′-dimethylformamide-κO)copper(II) dimethylformamide solvate

“…For studies of thiosemicarbazone complexes containing amino acids, see: Garcia-Orozco et al (2002); Seena et al (2007); Valdes-Martinez et al (1995); Singh et al (1997); Shen et al (1997); Zimmer et al (1991).…”