Trapping a Metastable Node in an Amorphous Metal-Organic Framework

We report the frustrated assembly of an amorphous metal-organic framework as a route to trap a metastable node within the network. Using x-ray pair distribution function (PDF) analysis and density functional theory (DFT), we show that a distorted node forms instead of the more commonly observed and energetically favorable symmetric node. We rationalise this via a kinetically controlled sequence in which network percolation precedes node relaxation, in contrast to crystalline MOFs, where distorted nodes are permitted by favourable topological stabilisation. Our results show that frustrated assembly is an effective mechanism to install non-equilibrium local motifs, establishing pathway control as a lever for node engineering in aMOFs.