Organyltellurium(IV) Complexes Derived from a Hydroxymethylfurfural Schiff Base: Synthesis, Single Crystal XRD, Structural, and Computational Characterization with Preliminary Biological Assessment

Growing drug resistance has prompted continued interest in new chemical scaffolds with biological potential. Herein, we report a series of organyltellurium(IV) complexes, HMeF4AP(TeCl4), HMeF4AP(R1TeCl3), and HMeF4AP(R2TeCl2), based on an underexplored Schiff base ligand (HMeF4AP) derived from 5-hydroxymethylfurfural and 4-aminophenol, obtained in 68–84% yields. The ligand structure was confirmed by single-crystal X-ray diffraction, revealing a monoclinic system and bidentate (NO) coordination, while spectroscopic and thermal analyses supported an octahedral geometry around Te(IV). The complexes showed measurable in vitro biological activity; complex 4d exhibited the most potent antioxidant activity (IC50 ≈ 2.72 μM), whereas 4e and 4f displayed strong antimicrobial and antitubercular activity. DFT calculations analyzed electronic properties and structure–activity trends, molecular docking explored microbial target interactions, and ADMET studies confirmed favorable drug-likeness and pharmacokinetic behavior. Overall, these results highlight organyltellurium Schiff base systems as chemically stable bioactive scaffolds, warranting further investigation, and support their relevance for future medicinal chemistry studies.