Related Experiment Video
Updated: Jan 18, 2026

Anticancer Metal Complexes: Synthesis and Cytotoxicity Evaluation by the MTT Assay
Published on: November 10, 2013
Comparative Study of Ni(II) Complexes with Dithiocarbazate- and Thiosemicarbazone-Based Ligands: Synthesis, Crystal
Gabriel S Pessoa1, Mariana P Viana1, Katia M Oliveira1
1Laboratory of Inorganic Synthesis and Crystallography, Institute of Chemistry, University of Brasilia, Brasília 70904-970, DF, Brazil.
Abstract:
The present work reports a comparative study of thiosemicarbazone (H2L1) and dithiocarbazate (H2L2) ligands and their Ni(II) complexes; [Ni(L1)(PPh3)] (1); [Ni(L1)(Py)] (2); [Ni(L2)(PPh3)] (3); and [Ni(L2)(Py)] (4). All compounds were characterized by spectroscopy analysis; and the complexes were also characterized by single-crystal X-ray diffraction. The crystal structures of the complexes revealed a distorted square planar geometry with the Ni(II) atoms coordinated to a double-deprotonated and tridentate ligand molecule by the ONS donor system. The coordination sphere is completed by the incorporation of pyridine or triphenylphosphine coligands at the metal center. Biological assays were conducted against the cell lines breast cancer (MCF-7); cisplatin-resistant ovarian cancer (A2780cis); lung cancer (A549); and nontumoral lung (MRC-5). The results show that cytotoxicity was significantly enhanced upon complexation for complexes (2) and (4); whereas it was suppressed for complexes (1) and (3) against the A2780cis and A549 cell lines. Notably; complex (2) exhibited superior cytotoxicity compared to cisplatin against both MCF-7 and A2780cis.
More Related Videos
Related Concept Videos
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Complexometric Titration: Ligands
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
EDTA: Chemistry and Properties

