I<sub>2</sub>‐Mediated Oxidation of Amines in Water toward Imines and Amides

Wang, Manman; Yu, Wenquan; Chang, Junbiao

doi:10.1002/ajoc.202300159

Cited by 1 publication

(1 citation statement)

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“…The COFs were fully characterized by BET, TGA, PXRD, solid-state NMR, and FT-IR (Figures S4–S10 and ). The reaction of PI-3-AR with chemical oxidants was tested in the presence of stoichiometric and excess of iodine, potassium peroxydisulfate and catalytic amount of nickel sulfate, and sodium hypochlorite. − Excess iodine was found to effectively convert the amine to the imine at the COF.…”

Section: Results and Discussionmentioning

confidence: 99%

Reversible Amine-to-Imine Chemistry at a Covalent Organic Framework for Sustainable Uranium Redox Separation

Wu,

Li,

Chen

et al. 2024

ACS Sustainable Chem. Eng.

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The interconversion chemistry of amine-to-imine sites in a covalent organic framework (COF) was developed for the redox-based separation of uranium. Compared to traditional approaches using sacrificial reagents or material decomposition for the reduction and separation of uranium, amine-COF served as the electron donor and was regenerated repeatedly following the oxidation and uranium reduction/separation. The amine-COF, PI-3-AR, was formed from the sodium borohydride (NaBH4) reduction of the imine-linked COF, PI-3, prepared from the solvothermal synthesis of 1,3,5-triformyl benzene (TFB) and 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)trianiline (TTA). PI-3-AR could be converted back to PI-3 via oxidative amination using an excess of the oxidant iodine, I2, or in the photochemical reduction of uranyl ions (UO2 2+). In consecutive photochemical uranium reduction and separation cycling experiments, the reduced amine COF, PI-3-AR, underwent: (i) oxidation alongside uranium photoreduction and deposition; (ii) acid treatment and uranium extraction; and (iii) NaBH4 reduction and material recovery. The COF, PI-3-AR, and novel separation process involving amine-to-imine interconversion effectively removed uranium (maximum adsorption = 278 mg U/g COF) and maintained >98% uranium recovery over five recycling steps at pH 4.0.

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Section: Results and Discussionmentioning

confidence: 99%