title: A metal-organic framework containing unusual eight-connected Zr-oxo secondary building units and orthogonal carboxylic acids for ultra-sensitive metal detection.
abstract: Two metal-organic frameworks (MOFs) with Zr-oxo secondary building units (SBUs) were prepared by using p,p'-terphenyldicarboxylate (TPDC) bridging ligands pre-functionalized with orthogonal succinic acid (MOF-1) and maleic acid groups (MOF-2). Single-crystal X-ray structure analysis of MOF-1 provides the first direct evidence for eight-connected SBUs in UiO-type MOFs. In contrast, MOF-2 contains twelve-connected SBUs as seen in the traditional UiO MOF topology. These structural assignments were confirmed by extended X-ray absorption fine structure (EXAFS) analysis. The highly porous MOF-1 is an excellent fluorescence sensor for metal ions with the detection limit of <0.5 ppb for Mn(2+) and three to four orders of magnitude greater sensitivity for metal ions than previously reported luminescent MOFs.
authors.affiliation: Department of Chemistry, University of Chicago, 929 E 57th Street, Chicago, IL 60637 (USA).
authors.forename: Michaël
authors.initials: M
authors.lastname: Carboni
authors.forename: Zekai
authors.initials: Z
authors.lastname: Lin
authors.forename: Carter W
authors.initials: CW
authors.lastname: Abney
authors.forename: Teng
authors.initials: T
authors.lastname: Zhang
authors.forename: Wenbin
authors.initials: W
authors.lastname: Lin
keywords: crystal structures; fluorescence sensing; functionalization; metal sensing; metal-organic frameworks