A Family of 2,8-Quinolinediol-Functionalized Titanium-Oxo Clusters with Tunable Photoelectric Properties

Abstract

Integrating functional ligands into titanium-oxo clusters (TOCs) represents a pivotal strategy for expanding their light-harvesting capabilities and structural diversity. Although various ligand systems have been extensively investigated, the assembly of TOCs using quinoline derivatives-a class of classical photoactive ligands-remains largely underdeveloped. In this work, 2,8-quinolinediol (H2QD) was employed as a versatile ligand to synthesize three novel TOCs, namely [Ti4(μ2-O)4(QD)4(DMF)4] (Ti4), [Ti5(μ3-O)2(QD)4(MeO)8] (Ti5), and [Ti7(μ2-O)(μ3-O)3(QD)(EtO)18] (Ti7), through a solvent-controlled synthetic strategy. Notably, structural analysis revealed that these clusters exhibit progressively increasing nuclearity and distinct inorganic core topologies. Benefiting from the incorporation of H2QD, all three clusters showed significantly extended light absorption reaching into the visible-light region. Furthermore, these clusters possessed tunable photoelectric properties, with Ti7 exhibiting superior performance compared to Ti4 and Ti5. This work introduces a promising quinoline-based ligand platform for the construction of structurally novel and functionally diverse TOCs.