Zr^IV Coordination Polymers Based on a Naturally Occurring Phenolic Derivative

Abstract

The reactivity under solvothermal conditions of the ZrIV ion with the naturally occurring gallic acid ligand has been evaluated in depth. The study led to the isolation of four microcrystalline hydroxycarboxylate‐based coordination polymers (MIL‐151 to ‐154). Through the use of a combination of solid‐state NMR and high‐resolution X‐ray powder diffraction analyses, the structures of two of these phases (MIL‐153, MIL‐154) were solved. In both cases, the gallol motifs favour the formation of rod‐like inorganic units built up from ZrO8 polyhedra. Although one compound (MIL‐151) was found to be microporous (SBET ≈ 470 m2 g–1), its poor crystallinity prevented comprehensive structural analysis. Nevertheless, a comparison of its physicochemical features with those of the fully characterized solids allows a plausible structural model to be proposed.

A Robust Infinite Zirconium Phenolate Building Unit to Enhance the Chemical Stability of Zr MOFs

“…These signals are attributed to seven carbon atoms out of the fourteen belonging to one whole TzGal ligand (as shown in Figure S12), thus corresponding to one half of TzGal instead of one quarter deduced by diffraction. Such ar esonance at particularly high isotropic chemical shift, which is also observed in MIL-153 [37] and MIL-157 (Figure S9), corresponds to av ery acidic proton bound to one of the two oxygen atoms the in meta position, as confirmed by the 2D 1 H-13 CNMR spectrum showing ac orrelation peak between this signal and the C(-O) atoms at d % 145-150 ppm (see Figure S10 and S14 for MIL-157 and MIL-163, respectively). Such ar esonance at particularly high isotropic chemical shift, which is also observed in MIL-153 [37] and MIL-157 (Figure S9), corresponds to av ery acidic proton bound to one of the two oxygen atoms the in meta position, as confirmed by the 2D 1 H-13 CNMR spectrum showing ac orrelation peak between this signal and the C(-O) atoms at d % 145-150 ppm (see Figure S10 and S14 for MIL-157 and MIL-163, respectively).…”

“…[37] To summarize,w er eport herein an ew porous Zr MOF built up from ar obust, 1D subunit arising from the 1,2,3trioxobenzene complexing group.Because of its composition, this solid has distinct stability attributes compared to archetypical Zr carboxylates:w hile its thermal stability is rather limited (ca. [37] To summarize,w er eport herein an ew porous Zr MOF built up from ar obust, 1D subunit arising from the 1,2,3trioxobenzene complexing group.Because of its composition, this solid has distinct stability attributes compared to archetypical Zr carboxylates:w hile its thermal stability is rather limited (ca.…”

“…Recently,through the systematic study of the reactivity of 3,4,5-trihydroxybenzoïc acid or gallic acid (see Scheme 1) with Zr IV salts in N,N-dimethylformamide (DMF), [37] we identified an ew one-dimensional coordination chain constituted solely from Zr IV and 1,2,3-trioxobenzene moieties.T his motif is built up of edge sharing ZrO 8 polyhedra, each Zr IV being surrounded by four ligands and each ligand chelating two Zr IV cations (see Figure S4 in the Supporting Information). From competitive coordination reactivity studies, [37] we also concluded that the 1,2,3-trioxobenzene moieties are more strongly bound to Zr IV than the carboxylate groups,thus leading in the case of gallic acid to ad ense 1D coordination polymer (MIL-153).…”

“…210 8 8C) compared to Zr carboxylate MOFs. [37] At lower temperature, solvent loss is accompanied by ashift and abroadening of the Bragg peaks ( Figure S18). [37] At lower temperature, solvent loss is accompanied by ashift and abroadening of the Bragg peaks ( Figure S18).…”

Expanding the Variety of Zirconium‐based Inorganic Building Units for Metal–Organic Frameworks

“…[5] As ac onsequence,asmall number of water based routes has been developed, which gave access to DMF free syntheses of functionalized UiO-66 derivatives [6] or Zr fumarate (MOF-801), [7] to name just some of the most prominent examples.In recent years our group,t ogether with cooperation partners, pushed these developments further by discovering multiple water-based synthesis routes for existing,but also completely new MOFs. [13][14][15][16] Molecular clusters of this composition have been intensively studied in the past and many supramolecular structures have emerged just recently. [13][14][15][16] Molecular clusters of this composition have been intensively studied in the past and many supramolecular structures have emerged just recently.…”