Spectrophotometric study of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) complexes with isatin-β-thiosemicarbazone

Abstract

The composition and stability of the complexes of isatin-?-thiosemicarbazone with Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) have been investigated using spectrophotometric method at 30?C and constant ionic strength of 0.1 mol dm-3 (KNO3) in 70 % ethanol. Experimental results indicate the formation of MeL and MeL2 complexes for Ni(II) and Co(II), and MeL for Cu(II), Zn(II), Pd(II) and Hg(II) complexes, whose stability constants, ?n, have been calculated using a computerized iterative method of successive approximation.

Synthesis and theoretical study of 5-methoxyisatin-3-(N-cyclohexyl)thiosemicarbazone and its Ni(II) and Zn(II) complexes

“…The electronic spectra of isatin-b-thiosemicarbazone show reference absorption bands of the aromatic ring (k 1 = 251 nm and k 2 = 281 nm) and the indole moiety due to transitions of the p-p* type and an absorption band at k 3 = 355 nm. In the case of the thiosemicarbazone part of the molecule, no transitions which could be assigned to an n-p* type were observed in the spectra, since they are covered with the more intensive p-p* type [21,22]. The electronic spectra of H 2 MICT ligand show primer absorption band at 372 nm due to a transition of the thiosemicarbazone part of the molecule pp* type, 292 nm, and 244 nm due to the aromatic ring and the indole moiety.…”

Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II), Cd(II), and Hg(II) Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

“…Schiff bases are very important class of ligands in coordination chemistry due to the wide applications of them in synthesis of a large variety of transition-metal complexes with various structural architectures [1][2][3][4][5]. ese ligands are oen prepared in suitable yields and purity during direct reaction between aldehyde or ketone and primary aromatic and/or aliphatic amines.…”

Synthesis, characterization, molecular modeling studies, and biological evaluation of metal piroxicam complexes (M = Ni(II), Pt(IV), Pd(II), Ag(I)) as antibacterial and anticancer agents

“…It was observed that the molar ratio of ligand/metal ion in the complex was 2:1 in case of divalent metals and 1:1 in case of Ag complex, and that went in line with elemental, mass analyses and previous literatures (Gehad & Nadia, 2004; Samra et al, 2022). By application of the continuous variation method and the reported mathematical equations, (Abdel‐Rahman et al, 2018; Konstantinović et al, 2007) the formation constant ( K f ), stability constant ( Log K f ) and Gibbs free energy ( ΔG ) were obtained at conditions of 25°C and pH of 7.4 as shown in Table 4. The obtained K f values depict the high stability of the investigated complexes.…”