High-capacity iodine adsorption from diverse media using iron-based metal–organic copolymer networks synthesized via a microwave-assisted Buchwald–Hartwig cross-coupling reaction

Abstract

Three-dimensional iron(II) clathrochelate-bridged secondary arylamine copolymers (TAC1–3) were synthesized via a facile microwave-assisted Buchwald–Hartwig cross-coupling reaction, utilizing a custom-designed diamine clathrochelate precursor along with a range of tribrominated aryl surrogates. The target copolymers exhibited impressive iodine vapor adsorption capabilities, with TAC3 achieving an outstanding uptake of 1500 wt% (15 g g⁻¹). Kinetic analysis identified a predominant pseudo-2nd-order adsorption model, whilst recyclability tests confirmed the materials’ durability, sustaining high efficiency albeit over multiple adsorption–desorption cycles. The TAC1–3 copolymers demonstrated notable iodine uptake from cyclohexane solutions with TAC3 achieving a maximum capacity of 1.11 g g⁻¹ at an initial iodine concentration of 1000 mg L⁻¹. Moreover, TAC1–3 demonstrated exceptional performance in aqueous systems, achieving adsorption capacities up to 5.95 g g⁻¹ in I₂ solutions and 5.34 g g⁻¹ in I₃⁻ (KI/I₂) solutions.