Crystallographic, Topological, Antidiabetic, and Docking Evaluation of an Azo-Enamine Ligand and its Triphenyltin(IV) Coordination Polymer The ligand 2-((E)-((Z)-3-(((2-hydroxyethyl)amino)methylene)-4-oxocyclohexa-1,5-dien-1-yl)diazenyl)benzoic acid (H3L) was synthesized and structurally characterized for the first time. Single-crystal X-ray diffraction study confirmed that H3L adopts a stable azo-enamine tautomeric form in solid state stabilized by intramolecular hydrogen bonding.