Synthesis of Metalorganic Copolymers Containing Various Contorted Units and Iron(II) Clathrochelates with Lateral Butyl Chains: Conspicuous Adsorbents of Lithium Ions and Methylene Blue

Published: 2022
Polymers 2022, 14(16), 3394

Abstract

We report the synthesis of three highly soluble metalorganic copolymers, TCP1–3, that were made from a one-pot complexation of iron(II) clathrochelate units that are interconnected by various thioether-containing contorted groups. TCP1–3 were converted into their poly(vinyl sulfone) derivatives OTCP1–3 quantitatively via the selective oxidation of the thioether moieties into their respective sulfones. All of the copolymers, TCP1–3 and OTCP1–3, underwent structural analysis by various techniques; namely, ¹H- and ¹³C-nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC). The copolymers were tested as potent lithium ions adsorbents revealing a maximum adsorption (q_m) value of 2.31 mg g⁻¹ for OTCP2. Furthermore, this same copolymer was found to be a promising adsorbent of methylene blue (MEB); an isothermal adsorption study divulged that OTCP2’s uptake of MEB from an aqueous solution (following the Langmuir model) was, at maximum adsorption capacity, (q_m) of 480.77 mg g⁻¹; whereas the kinetic study divulged that the adsorption follows pseudo second-order kinetics with an equilibrium adsorption capacity (q_e,cal) of 45.40 mg g⁻¹.