Remote Electrostatic Effect between Octahedral Ru/Ir‐Complexes and Aromatic Micelles to Improve Their Photofunctions in Water

ABSTRACT Unlike in aprotic solvents, cation–anion electrostatic interactions are seldom utilized in water owing to unavoidable hydration and thus the aqueous encapsulation of ionic guests is difficult even for (supra)molecular hosts. Here we report the effective encapsulation of cationic octahedral metal‐complexes (metal = Ru(II) and Ir(III)) in water by anionic aromatic micelles, composed of bent aromatic amphiphiles with anionic side chains. The formation of 1:1 host–guest composites and their high stability are revealed by NMR, UV–visible, DLS, AFM, TEM, and molecular modeling analyses. No or poor encapsulation is observed for cationic/nonionic analogues and other aqueous hosts under the same conditions, suggesting the presence of remote electrostatic effects between the cationic metal‐complexes and the anionic side chains. The emission enhancement (∼3 to 10‐fold) of the phosphorescent Ru/Ir‐complexes and a fluorescent organic dye is demonstrated upon (co‐)encapsulation by the anionic micelle under aerobic conditions. Moreover, the host–guest composite including the Ir‐complex co‐encapsulates a large amount of styrene derivatives in the adaptable cavity and the resultant, aqueous ternary composites undergo Ir‐complex‐catalyzed photopolymerization with high reactivity and reusability. The present, unusual host–guest interactions offer a new strategy to improve the photophysical and photocatalytic activities of cationic metal‐complexes upon simple encapsulation by anionic aromatic micelles in water.