Synthesis, X-ray crystal structure and BVS calculation of Co(II) complex of pyrimidine derived Schiff base ligand: Approached by Hirshfeld surface analysis and TDDFT calculation

Fluorometric Detection of Sodium Ion Using Bis(2,4-dihydroxyphenylmethylene)Thiocarbohydrazone; Crystal Structure, DFT Studies, Anti-Cancer Assay, ADMET Study and Molecular Docking

A simple fluorescent sensor, 1,5-bis(2,4-dihydroxyphenylmethylene)thiocarbohydrazone (H6L), was designed for the selective detection of sodium ions amidst other cations. The molecular structure of H6L was confirmed using the SCXRD method, which reveals significant hydrogen bonding interactions in the lattice. Hirshfeld surface analysis also confirms asubstantial contribution of O⋅⋅⋅H/H⋅⋅⋅O interactions (23.3%) to the total Hirshfeld surface. H6L exhibited enhanced fluorescence emission in response to Na+ with a detection limit of 40 × 10- 8 M, facilitated by the inhibition of the C = N based isomerisation and inhibition of the excited-state intramolecular proton transfer mechanism. The sensing capability of H6L towards Na+ ions was confirmed by electronic and IR spectra, theoretical studies, Job's plot and Benesi-Hildebrand method, collectively demonstrating ground-state complex formation and a 1:2 binding stoichiometry between H6L and Na+ ions. The sensor's practical application for detecting Na+ ions was demonstrated by creating sensor-coated paper strips. Additionally, the compound was evaluated for its in vitro anticancer activity against MCF7 breast cancer and A549 lung adenocarcinoma cell lines. The IC50 values indicate excellent cytotoxic activity against MCF7 cells (40.37 µg/mL) compared to A549 cells (82.30 µg/mL). To further explore the mechanisms underlying its anticancer activity, molecular docking studies were performed against enzyme targets 4IGK and 2ITO, which validate the in vitro findings.

Coupling 6-chloro-3-methyluracil with copper: structural features, theoretical analysis, and biofunctional properties

As nucleobases in RNA and DNA, uracil and 5-methyluracil represent a recognized class of bioactive molecules and versatile ligands for coordination compounds with various biofunctional properties. In this study, 6-chloro-3-methyluracil (Hcmu) was used as an unexplored building block for the self-assembly generation of a new bioactive copper(II) complex, [Cu(cmu)₂(H₂O)₂]·4H₂O (1). This compound was isolated as a stable crystalline solid and fully characterized in solution and solid state by a variety of spectroscopic methods (UV-vis, EPR, fluorescence spectroscopy), cyclic voltammetry, X-ray diffraction, and DFT calculations. The structural, topological, H-bonding, and Hirshfeld surface features of 1 were also analyzed in detail. The compound 1 shows a distorted octahedral {CuN₂O₄} coordination environment with two trans cmu^- ligands adopting a bidentate N,O-coordination mode. The monocopper(II) molecular units participate in strong H-bonding interactions with water molecules of crystallization, leading to structural 0D → 3D extension into a 3D H-bonded network with a tfz-d topology. Molecular docking and ADME analysis as well as antibacterial and antioxidant activity studies were performed to assess the bioactivity of 1. In particular, this compound exhibits a prominent antibacterial effect against Gram negative (E. coli, P. aeruginosa) and positive (S. aureus, B. cereus) bacteria. The obtained copper(II) complex also represents the first structurally characterized coordination compound derived from 6-chloro-3-methyluracil, thus introducing this bioactive building block into a family of uracil metal complexes with notable biofunctional properties.