The Inhibited Dehydration Polycondensation Tendency of a Titanocene Aqua Complex Attributed to the Formation of Hydrogen Bonds Between the Ligand Water and Py-NO: Mechanism and Application

Titanocene aqua complexes ( TACs ) demonstrate versatile activities that critically depend on maintaining their molecular integrity in aqueous media. However, the strong oxophilicity of Ti(IV) centers renders these complexes prone to undesirable dehydration-condensation reactions, which severely compromise their structural stability. To address this challenge, we developed a simple yet effective strategy for dramatically stabilizing TACs in aqueous environments through the introduction of pyridine-N-oxides ( Py-NOs ) as auxiliary ligands. Comprehensive mechanistic investigations, including spectroscopic analyses and DFT calculations, reveal that the enhanced stability originates primarily from the formation of intermolecular hydrogen bonds between TACs and Py-NOs . These interactions effectively suppress Ti(IV)-mediated hydrolysis pathways while preserving the complexes’ functionality.