Gauging substituent effect of organic counteranion in hybrid MOFs derived from γ-cyclodextrin: silver nanoparticle formation as test reaction†

Abstract

A new class of hybrid MOFs were prepared based on γ-cyclodextrin (γ-CD) and food-origin organic acids via crystal growth utilizing γ-CD as a primary building block and food-origin organic acids as a secondary building block; this was done as part of an organic counteranion co-assembly strategy. Three food-origin organic acids, cinnamic acid, coumaric acid, and ferulic acids, were converted into respective potassium salts. Subsequently, by applying a co-assembly strategy with γ-CD via crystal growth, hybrid MOFs were prepared. These organic counteranions, cinnamate, coumarate, and ferulate, were selected to build the hybrid γ-CD MOF to unravel the substituent effect of functional groups in the backbone of organic counteranion on the properties of the hybrid CD MOFs. The effect of changing the crystallization solvent on the overall charge balance of these hybrid γ-CD MOFs during organic counteranion co-assembly was evaluated through ¹H and ¹³C inverse-gated ¹H decoupled spectra. In addition, we also report the use of the formation reaction of silver nanoparticles to test the effect of substituents on the stability of hybrid CD MOFs derived from γ-CD and food-origin organic acids.