Ionothermal Synthesis and Photoactivity of Ti₁₇ and Ti₁₉‐Oxo Clusters Functionalized by Sulfate and 1,10‐Phenanthroline Ligands

Comprehensive Summary In this study, we successfully synthesized two titanium‐oxo clusters, namely Ti 19 (μ 3 ‐O) 19 (μ 2 ‐O) 10 (1,10‐phn) 2 (O i Pr) 18 ] ( PTC‐178 ) and (EMIm) 3 [Ti 17 (μ 4 ‐O) 4 (μ 3 ‐O) 16 (μ 2 ‐O) 4 (SO 4 ) 3 (μ 2 ‐O i Pr) 4 (O i Pr) 13 ] ( PTC‐179 ). These clusters were synthesized using an ionothermal reaction and possess similar nuclearity (Ti 19 vs. Ti 17 ) moieties. Additionally, we observed that these complexes exhibit varying activities for photocatalytic degradation of Methylene Blue (MB) dye and distinct photocurrent responses for photoelectrochemical studies due to their different surface‐decorated ligands. This study provides valuable insights into the design of Ti‐oxo molecular clusters with similar nuclearity but different surface environments, allowing for the establishment of critical structure‐property relationships. Furthermore, our research contributes to the exploration of sustainable synthetic methods for high nuclearity TOCs using ionic liquids.