Addition of small quantities of amino acids to solvothermal and microwave syntheses of Zr and Hf MOFs drastically improves their crystallinity to the extent that single crystal structures can be obtained.

Whilst many metal–organic frameworks possess the chemical stability needed to be used as functional materials, they often lack the physical strength required for industrial applications. Herein, we have investigated the mechanical properties of two UiO‐topology Zr‐MOFs, the planar UiO‐67 ([Zr6O4(OH)4(bpdc)6], bpdc: 4,4′‐biphenyl dicarboxylate) and UiO‐abdc ([Zr6O4(OH)4(abdc)6], abdc: 4,4′‐azobenzene dicarboxylate) by single‐crystal nanoindentation, high‐pressure X‐ray diffraction, density functional theory calculations, and first‐principles molecular dynamics. On increasing pressure, both UiO‐67 and UiO‐abdc were found to be incompressible when filled with methanol molecules within a diamond anvil cell. Stabilization in both cases is attributed to dynamical linker disorder. The diazo‐linker of UiO‐abdc possesses local site disorder, which, in conjunction with its longer nature, also decreases the capacity of the framework to compress and stabilizes it against direct compression, compared to UiO‐67, characterized by a large elastic modulus. The use of non‐linear linkers in the synthesis of UiO‐MOFs therefore creates MOFs that have more rigid mechanical properties over a larger pressure range.

Whilst many metal-organic frameworks possess the chemical stability needed to be used as functional materials, they often lackt he physical strength required for industrial applications.H erein, we have investigated the mechanical properties of two UiO-topology Zr-MOFs,t he planar O 4 (OH) 4 (bpdc) 6 ], bpdc:4 ,4'-biphenyl dicarboxylate) and O 4 (OH) 4 (abdc) 6 ], abdc:4 ,4'-azobenzene dicarboxylate) by single-crystal nanoindentation, high-pressure X-rayd iffraction, density functional theory calculations, and first-principles molecular dynamics.O ni ncreasing pressure,b oth UiO-67 and UiO-abdc were found to be incompressible when filled with methanol molecules within ad iamond anvil cell. Stabilization in both cases is attributed to dynamical linker disorder.T he diazo-linker of UiO-abdc possesses local site disorder,w hich,i nc onjunction with its longer nature,also decreases the capacity of the framework to compress and stabilizes it against direct compression, compared to UiO-67, characterized by alarge elastic modulus.The use of non-linear linkers in the synthesis of UiO-MOFs therefore creates MOFs that have more rigid mechanical properties over alarger pressure range.

A new member of the UiO-66 series of zirconium metal-organic frameworks (MOFs) is reported, and the postsynthetic bromination of its integral alkene moeities in a single-crystal to single-crystal manner is fully characterised. Nanoindentation is used to probe the bromination of unsaturated carbon-carbon bonds, in it and an analogous Zr MOF, which leads to more compliant materials with lower elastic moduli.