The structural arrangement of the ligand-metal complex with centered zinc and nickel atoms and their optical features

Synthesis, X-ray Crystal Structure, Anticancer, Hirshfeld Surface Analysis, DFT, TD-DFT, ADMET, and Molecular Docking of 3-Phenyl-1,2,4-triazolo[3,4-h]-13,4-thiaza-11-crown-4

In this work, we describe the synthesis of new macrocycles derived from 3-phenyl-1,2,4-triazole-5-thione 1 in a heterogeneous medium using liquid–solid phase transfer catalysis (PTC) conditions. The structures of the two compounds (3 and 4) isolated were elucidated based on spectral data (1H-NMR, 13C-NMR) and confirmed in the case of 3-phenyl-1,2,4-triazolo [3,4-h]-13,4--thiaza-11-crown-4 (3) by a single-crystal X-ray diffraction analysis. Furthermore, the experimental spectral and the X-ray geometrical parameters were compared with their corresponding predicted ones obtained at the B3LYP/6-311++G(d,p) level of theory. The intercontacts between crystal units were investigated through Hirshfeld surface analysis. The drug-like macrocycles were predicted using ADMET and drug-likeness properties, which showed that 3 may act as an inhibitor of DNA-dependent protein kinase (DNA-PK). This assumption was confirmed by the well-binding fitting of 3 into the binding site of DNA-PK and the formation of a stable 3-DNA-PK complex with a binding energy of −7 kcal-mol−1. Finally, the anticancer activity of 3 was assessed by an MTT assay against A549 cells, which showed that 3 has moderate anticancer activity compared to that of the doxorubicin reference drug.

Solvatochromism, Acidochromism and Photochromism of the 2,6-Bis(4-hydroxybenzylidene) Cyclohexanone Derivative

In this paper, we studied the photophysical behavior of 2,6-bis(4-hydroxybenzylidene) cyclohexanone (BZCH) under the influence of various stimuli. The photophysical properties were correlated with different solvent parameters, such as the Kamlet–Abraham–Taft (KAT), Catalán, and Laurence solvent scales, suggesting that the behavior of BZCH is influenced by both nonspecific and specific solvent-solute interactions. The Catalán solvent dipolarity/polarizability parameters were found to have a significant role in the solvatochromic behavior, which is also confirmed by the KAT and Laurence models. The acidochromism and photochromism properties of this sample in dimethylsulfoxide and chloroform solutions were also investigated. The compound showed reversible acidochromism after the addition of dilute NaOH/HCl solutions, accompanied by a change in color and the appearance of a new absorption band (514 nm). The photochemical behavior was also examined by irradiating BZCH solutions with both 254 and 365 nm light.

Ligand-Modulated Nuclearity and Geometry in Nickel(II) Hydrazone Complexes: From Mononuclear Complexes to Acetato- and/or Phenoxido-Bridged Clusters

The propensity of 4-hydroxybenzhydrazone-related ligands derived from 3-methoxysalicylaldehyde (H₂L^3OMe), 4-methoxysalicylaldehyde (H₂L^4OMe), and salicylaldehyde (H₂L^H) to act as chelating and/or bridging ligands in Ni(II) complexes was investigated. Three clusters of different nuclearities, [Ni₃(L^3OMe)₂(OAc)₂(MeOH)₂]∙2MeOH∙MeCN (1∙2MeOH∙MeCN), [Ni₂(HL^4OMe)(L^4OMe)(OAc)(MeOH)₂]∙4.7MeOH (2∙4.7MeOH), and [Ni₄(HL^H)₂(L^H)₂(OAc)₂]∙4MeOH·0.63H₂O·0.5MeCN·HOAc (3∙4MeOH·0.63H₂O·0.5MeCN·HOAc), were prepared from Ni(OAc)₂∙4H₂O and the corresponding ligand in the presence of Et₃N. The hydrazones in these acetato- and phenoxido-bridged clusters acted as singly or doubly deprotonated ligands. When pyridine was used, mononuclear complexes with the square-planar geometry seemed to be favoured, as found for complexes [Ni(L^3OMe)(py)] (4), [Ni(L^4Ome)(py)] (5) and [Ni(L^H)(py)] (6). Ligand substituent effects and the stability of square-planar complexes were investigated and quantified by extensive quantum chemical analysis. Obtained results showed that standard Gibbs energies of binding were lower for square-planar than for octahedral complexes. Starting from [MoO₂(L)(EtOH)] complexes as precursors and applying the metal-exchange procedure, the mononuclear complexes [Ni(HL^3OMe)₂]∙MeOH (7∙MeOH) and [Ni(HL^H)]∙2MeOH (9∙2MeOH) and hybrid organic-inorganic compound [Ni₂(HL^4OMe)₂(CH₃OH)₄][Mo₄O₁₀(OCH₃)₆] (10) were achieved. The octahedral complexes [Ni(HL)₂] (7-9) can also be obtained by the direct synthesis from Ni(Oac)₂∙4H₂O and the appropriate ligand under specific reaction conditions. Crystal and molecular structures of 1∙2MeOH∙MeCN, 2∙4.7MeOH, 3∙4MeOH∙0.63H₂O∙0.5MeCN∙HOAc, 4, 5, 9∙2MeOH, and 10 were determined by the single-crystal X-ray diffraction method.