(Z)-4,4′-Stilbene dicarboxylic acid, the overlooked metal–organic framework linker

Abstract

Metal–organic frameworks exhibit a broad and diverse structural portfolio, with rational structural engineering of frameworks becoming increasingly desirable. Fine-tuning the metal–ligand combination offers a simple way to adjust a framework's physical and chemical properties. One route to synthesising frameworks with new physical properties and topologies without altering the chemical composition is through the use of ligand isomers. Whilst trans-stilbene derivatives, such as (E)-4,4′-stilbene dicarboxylic acid have been exhaustively studied producing numerous unique frameworks, its ligand-originated isomer, cis-stilbene derivative (Z)-4,4′-stilbene dicarboxylic acid has not. Herein, we describe the synthesis of ten lanthanide (Z)-4,4′-stilbene dicarboxylic acid frameworks, five possessing non-interpenetrating 2D sheet structures and five microporous 3D frameworks with 1-dimensional pore channels that incorporate internal voids of up to 5.2 Å in diameter. These three-dimensional frameworks have a hitherto unrecognised underlying net topology, now registered as lmj1.