Synthesis, structural characterization, and density functional theory calculations of the two new Zn (II) complexes as antibacterial and anticancer agents with a neutral flexible tetradentate pyrazole‐based ligand

Abstract

Two new mono‐ and dinuclear zinc (II) complexes with a formula of [Zn (LN)OMeCl] (1) and [Zn2(LN)(N3)2Cl2] (2) [where LN = 1,1,3,3‐tetrakis(3,5‐dimethyl‐1‐pyrazolyl)propane)] have been synthesized in methanol as a solvent and fully characterized by the single crystal X‐ray diffraction, elemental analysis, FT‐IR, UV–Vis, density functional theory (DFT) calculations, antibacterial, and anticancer properties. In both of them, zinc ion is tetrahedrally coordinated to two nitrogen atoms from one of the chelating bidentate bis(3,5‐dimethylpyrazolyl)methane units of the LN ligand and one terminal chlorine. The forth coordination site was occupied by methoxy group in 1 and azide co‐ligand in complex 2. In contrast to 1, in the structure of 2 two metal centers are bridged by the tetradentate chelating LN ligand to form a dinuclear complex. Interestingly, the environment around the central atom in these complexes are mimicked with the core structure of the zinc metalloproteinases, Thermolysin {[NNO]ZnX} and Carbonic anhydrase {[NNN]ZnX} for complexes 1 and 2, respectively. Data analysis of the antibacterial activities demonstrated that the gram positive species showed more sensitivity toward the target title agents. Although, both complexes exhibit antibacterial activities and kill bacteria at low concentration, but complex 1 has higher DNA cleavage activity than 2. Additionally, the cytotoxicity of the free ligand and its complexes was evaluated against the human carcinoma cell line (Caco‐2) by the MTT method and the IC50 values were calculated for all of them. Due to the presence of pyrazole rings in the structure of the ligand and its complexes, these materials have a substantial potential to inhibit cancer cell metastasis. The energetic stabilization due to donor‐acceptor interactions in terms of the natural bond orbital (NBO) analyses and nonlinear optical properties were also examined by using the DFT calculations.

Zinc(II) Complex Containing Oxazole Ring: Synthesis, Crystal Structure, Characterization, DFT Calculations, and Hirshfeld Surface Analysis

“…According to DFT calculations, Beheshti et al reported the synthesis of a pyrazolyl-based mononuclear zinc(II) complex with a 4.59 eV HOMO-LUMO energy gap. 37 The HOMO-LUMO energy gap value of the zinc(II) complex based on the benzoyl hydrazone ligand was calculated by the DFT method to be 3.76 eV in 2017. 38 As a result, the synthesized zinc(II) complex in this study is less stable than those that have been previously described.…”

Synthesis, Crystal Structures, H2S, and Iodine Uptake Properties of Four New Coordination Polymers Constructed from Group 12 Transition Metal Ions and a Bidentate Sulfur Donor Ligand

“…Recently, various coordination polymers (CPs), metal organic frameworks (MOFs), and covalent organic frameworks (COFs) have been reported as new candidates for the removal of iodine. ,, In the structure of these polymers, the nature of metals, kind of ligands, counterions, type of solvents, and reaction conditions play a vital role. Alternatively, there is a rapid growth in the manufacturing of the ligands with O, N, and S donor atoms to use in the CPs and MOFs. − In particular, the systematic designs of sulfur-containing ligands have been investigated in bioinorganic chemistry and for their ability to create various coordination network architectures. , Following our ongoing research on the development of coordination polymers with S donor ligands, ,, herein, we report four novel metal–organic frameworks with d 10 transition metals of group 12 and L s (pbit) ligand [where L s or pbit = 1,1′-(pentane-1,5-diyl)­bis­(-3-methyl-1 H -imidazole-2-thione)]. The title polymers were applied as an adsorbent for hydrogen sulfide and also used for iodine removal.…”

High incorporation of magnetite nanoparticles inside tetraaza macrocyclic Schiff base cavity: spectroscopic characterization and modeling by DFT calculation

“…In fact, macrocyclic Schiff bases are particularly important in macrocyclic chemistry because of their exible synthesis, their selectivity, and even their ability to stabilize many metals in various oxidation states [12][13][14][15][16]. However, a huge number of tetraaza macrocyclic (N 4 ) metal complexes show interesting biological activities such as antifungal [17,18], antibacterial [19][20][21], antimicrobial [22][23][24][25] and anticancer [11,26,27] effects.…”