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 (<b>TACs</b>) 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 <b>TACs</b> in aqueous environments through the introduction of pyridine-N-oxides (<b>Py-NOs</b>) 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 <b>TACs</b> and <b>Py-NOs</b>. These interactions effectively suppress Ti(IV)-mediated hydrolysis pathways while preserving the complexes' functionality.