Partial and Complete Substitution of the 1,4-Benzenedicarboxylate Linker in UiO-66 with 1,4-Naphthalenedicarboxylate: Synthesis, Characterization, and H-Adsorption Properties.

We describe the synthesis and corresponding full characterization of the set of UiO-66 metal-organic frameworks (MOFs) with 1,4-benzenedicarboxylate (CH(COOH), hereafter HBDC) and 1,4-naphthalenedicarboxylate (CH(COOH), hereafter HNDC) mixed linkers with NDC contents of 0, 25, 50, and 100%. Their structural (powder X-ray diffraction, PXRD), adsorptive (N, H, and CO), vibrational (IR/Raman), and thermal stability (thermogravimetric analysis, TGA) properties quantitatively correlate with the NDC content in the material. The UiO-66 phase topology is conserved at all relative fractions of BDC/NDC.

Water as a structure-driving agent between the UiO-66 and MIL-140A metal-organic frameworks.

We report a careful investigation of a selective phase formation in the zirconium-terephthalic acid system during solvothermal synthesis, which could result in the UiO-66 (Zr6O6(OH)4(BDC)6) or MIL-140A (ZrO(BDC)) metal-organic frameworks (MOFs). The introduction of water varies the phase from MIL-140A to UiO-66 by producing at the nucleation stage tetragonal ZrO2 nanoparticles, where the local arrangement of Zr and O atoms is similar to that in the UiO-66 SBU.