A mononuclear copper(II) complex based on the polypyridyl ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz), [Cu(tptz)2]2+: X-ray crystal structure, DNA binding and in vitro cell cytotoxicity

A structural and biological study on the new 3,5-diacetyl-1,2,4-triazol bis(p-chlorophenylthiosemicarbazone) ligand and its bimetallic complexes

Preparation and characterization of the new ligand 3,5-diacetyl-1,2,4-triazol bis(⁴N-p-chlorophenylthiosemicarbazone), H₅L¹, and its bimetallic complexes [Pd(μ-H₃L¹)]₂ and [Pt(μ-H₃L¹)]₂, are described.

(Un)suitability of the use of pH buffers in biological, biochemical and environmental studies and their interaction with metal ions – a review

The present work reviews, discusses and update the metal complexation characteristics of thirty one buffers commercially available. Additionally, their impact on the biological systems is also presented and discussed.

Spectroscopic, analytical and DFT calculation studies of two novel Al3+ complexes derived from 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPTZ)

In this study TPTZ is used exclusively as an analytical reagent for the determination of micro amounts of Al3+ ions with high accuracy and lower detection limit, which reach 2.7 ppm. The developed blue color of Al3+-TPTZ complex was used selectivity to determine the concentration and the geometry of the Al3+ complex using continuous variation and molar ratio methods. Also, the novel Al3+ complexes derived from the reaction of TPTZ were synthesized. The solid complexes were characterized by elemental analyses, spectral (IR, UV-vis., 1H NMR, mass) and magnetic measurements. The isolated complexes have the general formulae, [Al(TPTZ)Cl3]·H2O·1½EtOH (1:1; M:L) and [Al2(TPTZ)Cl6(EtOH)2] (2:1; M:L). IR spectra indicate that TPTZ behaves in a bidentate manner in case of 1:1 and 2:1 (M:L). Elemental analyses and mass spectra of the complexes suggest the existence of an octahedral structure around the Al3+ ions. DFT calculations were used to determine the geometry of complexes.

DNA- and BSA-binding studies and anticancer activity against human breast cancer cells (MCF-7) of the zinc(II) complex coordinated by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine

Binding studies of a mononuclear zinc(II) complex, [Zn(dppt)2Cl2] (dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine), with DNA and bovine serum albumin (BSA) have been investigated under physiological conditions. The binding properties of the complex with fish sperm DNA (FS-DNA) have been investigated by UV-Vis absorption, thermal denaturation, competitive DNA-binding studies with ethidium bromide (EB) by fluorescence, and gel electrophoresis techniques. The competitive study with (EB) shows that the complex can displace EB from the DNA-EB system and compete for the DNA-binding sites with EB, which is usually characteristic of the intercalative interaction of compounds with DNA. The value of the fluorescence quenching constant (Ksv) was obtained as 3.1×10(4)M(-1), indicating that this complex shows a high quenching efficiency and a significant degree of binding to DNA. Moreover, the intercalative binding mode has also been verified by the results of UV-Vis absorption, thermal denaturation and gel electrophoresis. The value of Kb at room temperature was calculated to be 1.97×10(5)M(-1), indicating that the complex possesses strong tendency to bind with DNA. This value is very greater than to the values obtained for other zinc(II) complexes. The interaction of the complex with BSA has been studied by UV-Vis absorption, fluorescence and circular dichroism (CD) spectroscopic techniques. The results indicate that the complex has a quite strong ability to quench the fluorescence of BSA and the binding reaction is mainly a static quenching process. The quenching constants (KSV), the binding constants (Kb), the number of binding sites at different temperatures, the binding distance between BSA and the complex (r), and the thermodynamic parameters (ΔH(o), ΔS(o) and ΔG(o)) between BSA and the complex were calculated. The complex exhibits good binding propensity to BSA showing relatively high binding constant values. The positive ΔH(o) and ΔS(o) values indicate that the hydrophobic interaction is main force in the binding of the complex to BSA. Moreover, to evaluate the anticancer properties, the cytotoxicity of the complex has been tested against the human breast adenocarcinoma (MCF-7) cell lines using the MTT assay. The results indicate that the parent complex displays cytotoxicity against human breast cancer cell lines (MCF-7) with an IC50 value of 10.44μM. It is remarkable that the complex can introduce as a potential anticancer drug.

Structural comparative studies on new Mn(II), Cr(III) and Ru(III) complexes derived from 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPTZ)

The structure of a new Mn(II) complex, [Mn(TPTZ)Cl2(H2O)]⋅H2O, was established by a single crystal X-ray diffraction. Crystal data are as follow: monoclinic, P21/c,a = 8.7202 (3)Å, b = 11.5712 (4)Å, c = 20.8675 (9)Å, β=11 (18) × 1010, V = 2029.27 (13)Å(3), Z = 4. The HOMO, LUMO and other DFT parameters on the atoms have been calculated to confirm the geometry of the ligand and its complexes using material studio program. The complexes were characterized by elemental analyses, spectral, magnetic, thermal and cyclic voltammetry measurements. Electronic spectra and magnetic moments of the complexes suggest distorted-octahedral structures around the metal ions (Mn(II), Cr(III) and Ru(III)). The redox properties were investigated by cyclic voltammetry. Kinetic parameters were determined using Coats-Redfern and Horowitz-Metzger methods. The results of DNA studies of the metal complexes promised to be effective in tumour treatment.

Comparative studies and modeling structures of two new isomers containing binuclear PdII complexes derived from 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPTZ)

The synthesis and comparative studies of two new binuclear PdII isomer complexes derived from TPTZ, [2,4,6-tri-(2-pyridyl)-1,3,5-triazine], have been synthesized and characterized. Their structures have been investigated by elemental analyses, spectral (IR, UV-vis, mass and 1H-NMR) and thermal measurements. Electronic and magnetic studies suggest a distorted square-planar around the two PdII ions. The HOMO, LUMO and DFT parameters on the atoms have been calculated to confirm the geometry of the ligand and their complexes. Kinetic parameters were determined using Coats-Redfern and Horowitz-Metzger methods. Also, the geometry of the two isomers is confirmed using DFT method from DMOL3 calculations. Moreover, the two PdII complexes have different specific optical rotation where the red PdII complex has dextrorotatory (+5.68) while the yellow PdII complex has levorotatory (-9.37). The results of biological activity for the two PdII complexes promised to be effective in tumor treatment.