Assembly of Two Mesoporous Anionic Metal-Organic Frameworks for Fluorescent Sensing of Metal Ions and Organic Dyes Separation

Anionic metal-organic frameworks (MOFs) have attracted increasing attention due to the enhanced electrostatic interactions between their anionic frameworks and counter-ionic guests. Owing to these special host-guest interactions, anionic MOFs are beginning to have a large impact in the field of absorption and separation of ionic molecules and selective sensing of metal ions. Herein, two mesoporous anionic metal-organic frameworks, namely, [(CH3)(2)NH2](6)[In-6(OX)(6)(TCA)(4)]center dot solvents (JOU-11) and [(CH3)(2)NH2](6)[In-6(OX)(6)(TCPA)(4)]center dot solvents (JOU-12) (H(3)TCA = tricarboxy-triphenylamine; H(3)TCPA = tris((4-carboxyl)phenylduryl)amine; OX = oxalate), have been synthesized by using wheel-type [In-6(OX)(6) (COO)(12)](6-) as building blocks. Structural analyses show that JOU-11 and JOU-12 show isoreticular three-dimensional frameworks with pyr topology. Due to their anionic frameworks and tunable pore window sizes, both compounds can be exploited for absorbing and separating cationic organic dyes. In addition, OU-11 can be developed as a fluorescence turn-off sensor for selectively sensing Fe3+, whereas JOU-12 can be used for fluorescence turn-on sensing of Cu2+ and Co2+- ions.

Automated summary

Anionic metal-organic frameworks with enhanced electrostatic interactions are synthesized, showing potential for absorption, separation, and selective sensing of ionic molecules. Two mesoporous anionic MOFs, JOU-11 and JOU-12, exhibit promising applications in absorbing and separating cationic organic dyes, as well as selectively sensing Fe3+, Cu2+, and Co2+ ions through fluorescence processes.