Microporous, Crystalline, and Water-Processable Framework Materials of Organic Amphiphile Salts

摘要

Porous framework materials are of major importance for a wide range oftechnologies. Nevertheless, many of these materials lack processibility as theyare typically synthesized under rather harsh conditions and obtained asmicrocrystalline powders that cannot easily be coated or deposited fromsolution. Herein, a new approach to water-processable metal–organicframework materials is presented. The materials are based on amphiphilicorganic building blocks consisting of polar carboxylate groups and non-polaralkyl chains connected to a rigid aromatic core. The amphiphilic buildingblocks assemble to porous framework structures via bonding to kineticallylabile sodium ions from concentrated aqueous solution. The obtainedcrystalline materials, termed amphiphile salt frameworks , are thermally andmechanically stable (some derivatives up to 365 ℃ and up to at least 4000 barhydrostatic pressure), exhibit persistent microporous channels accessible toseveral gases (N_2, CO_2, propane, propylene, n-butane), and can be reversiblyassembled/disassembled by crystallization from or dissolution in water.Systematic variation of the hydrophobic side chains of the amphiphile buildingblocks allows extracting structure-property relationships and first design rulesfor this new class of water-processable microporous framework materials.