1D, 2D and 3D cadmium(II) polymeric complexes with quinoline-4-carboxylato anion, quinazoline and 2,5-dimethylpyrazine

X-ray Structure Analyses and Biological Evaluations of a New Cd(II) Complex with S-Triazine Based Ligand

The crystal structure of a new penta-coordinated Cd(II) complex of the formula [Cd(BPMT)Br2] was presented. This Cd(II) complex was synthesized by mixing Cd(NO3)2·4H2O and 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) in the presence of KBr. It crystallized in the monoclinic crystal system and P21/n space group. The crystal parameters are a = 11.3680(8) Å, b = 11.1648(8) Å, c = 15.8593(11) Å, and β = 103.563(2)°, while the unit cell volume is 2190.6(12) Å3 and it comprised four molecules. The supramolecular structure of the [Cd(BPMT)Br2] complex is mainly controlled by the intermolecular Br∙∙∙H interactions. Hirshfeld calculations predicted the H∙∙∙H (38.1%), Br∙∙∙H (24.3%), C∙∙∙H (11.1%), and N∙∙∙H (9.5%) interactions are the most dominant. Biological evaluations for the antimicrobial and anticancer properties of the studied complex are presented. The Cd(II) complex has better anticancer and antibacterial activities than the free BPMT ligand. The anticancer activity against lung carcinoma (A-549) is higher for the former (18.64 ± 1.09 µg/mL) compared to the latter (372.79 ± 13.64 µg/mL). Additionally, the best antibacterial activity for the Cd(II) complex was found against B. subtilis.

Molecular, Supramolecular Structures Combined with Hirshfeld and DFT Studies of Centrosymmetric M(II)-azido {M=Ni(II), Fe(II) or Zn(II)} Complexes of 4-Benzoylpyridine

The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]; 1, [Ni(4bzpy)4(N3)2]; 2 and [Zn(4bzpy)2(N3)2]n; 3 with 4-benzoylpyridine (4bzpy) were presented. All complexes contain hexa-coordinated divalent metal ions with a slightly distorted octahedral MN6 coordination sphere. Complexes 1 and 2 are monomeric with terminal azido groups while 3 is one-dimensional coordination polymer containing azido groups with μ(1,1) and μ(1,3) bridging modes of bonding. Hirshfeld analysis was used to quantitatively determine the different contacts affecting the molecular packing in the studied complexes. The most common interactions are the polar O…H and N…H interactions and the hydrophobic C…H contacts. The charges at the M(II) sites are calculated to be 1.004, 0.847, and 1.147 e for complexes 1–3, respectively. The degree of asymmetry is the highest in the case of the terminal azide in complexes 1 and 2 while was found the lowest in the μ(1,1) and μ(1,3) azide bonding modes in the Zn(II) complex 3. These facts were further explained in terms of atoms in molecules (AIM) topological parameters.

Zinc(II) complexes with aromatic nitrogen-containing heterocycles as antifungal agents: Synergistic activity with clinically used drug nystatin

Three novel Zn(II) complexes, [ZnCl₂(qz)₂] (1), [ZnCl₂(1,5-naph)]_n (2) and [ZnCl₂(4,7-phen)₂] (3), where qz is quinazoline, 1,5-naph is 1,5-naphthyridine and 4,7-phen is 4,7-phenanthroline, were synthesized by the reactions of ZnCl₂ and the corresponding N-heterocyclic ligand in 1:2 molar ratio in ethanol at ambient temperature. The characterization of these complexes was done by NMR, IR and UV-Vis spectroscopy, and their crystal structures were determined by single-crystal X-ray diffraction analysis. Complexes 1 and 3 are mononuclear species, in which Zn(II) ion is tetrahedrally coordinated by two nitrogen atoms belonging to two qz or 4,7-phen ligands, respectively, and by two chloride anions, while complex 2 is a 1D coordination polymer that contains 1,5-naph as bridging ligand between two metal ions. In agar disc-diffusion assay, complexes 1-3 manifested good inhibitory activity against two investigated Candida strains (C. albicans and C. parapsilosis), while not inducing toxic effects on the healthy human fibroblast cell line (MRC-5). This activity was not fungicidal, as revealed by the broth microdilution assay, however complex 3 showed the ability to modulate Candida hyphae formation, which is an important process during infection and showed significant synergistic effect with clinically used antifungal polyene nystatin.