Uranyl Phosphonic Acid Complexes And Its Functionalized Covalent Organic Nanosheets Were Removed In Vivo

This paper focuses on the supramolecular coordination recognition of uranium and mainly explores the synthesis of uranyl-bearing coordination compounds and the study on the removal of uranyl ions in vivo by covalent organic nanosheets.Rraction of uranyl and phenylenediphosphonic acid,uranyl-organic coordination polymer was constructed,through urany coodrinated nitrogen and oxygen atoms from acid ligand.The result will provide detail coordination sites and mechanism of supramolecular recognition between uranyl ion and fucntional groups,in order to achieve the removal of uranyl ion,including amidoxime.Covalent organic frameworks?COFs?materials are a new class of materials synthesized via the covalent bonding of light elements.COFs materials have advantages of highly ordered porous structure,adjustable pore size,and large specific surface area.However,COFs generally adopts relatively large particle size,moderate biocompatibility and limited number of active functional sites.In comparison,covalent organic nanosheets?CONs?with more chelation sites and more contact space could be obtained by the exfoliation of COFs via post-modification and ultrasound methods.Additionally,in this work,the structural chemistry and the photoluminescence property of a uranyl-bearing metal-organic polymer have been studied.The details are as follows:?1?Reaction of 1,2-phenylenediphosphonic acid?H₄PDPA? with UO₂?NO₃?₂�6H₂O and AgNO₃ yielded a new 2D layered silver uranylphosphonatecompound,Ag⁰_1.51[Ag₄^I?UO₂?₃[(C₆H₄?PO₃?₂][(C₆H₄?PO₃??PO₃H?]₂]under the mild hydrothermal condition.The uranyl layer consists of two kinds of UO₈ and UO₇coordination units simultaneously connected by phenylenediphosphonate ligands.This study provides structural support for the coordination pattern of uranyl ions.To our surprise,the presence of both silver ions and metallic silver atoms in the free space between the layers is identified by the single crystal X-ray diffraction,EDS,and XPS techniques.The ratio of Ag⁺and Ag⁰ was estimated to be 2.81:1,based on the primary peak area of Ag 3d_5/2 from the XPS results,which corroborates with the ratio of 2.65:1 obtained from the XRD results.More importantly,the incorporation of mixed-valent silver sites results in the quenching of the fluorescent emission of the uranyl phosphonate compound as evidenced by the single crystal fluorescence spectrum.?2?Compared with small molecular decorporation drugs,nanomaterials have several merits including low biotoxicity,good biocompatibility,and controllable release,indicating that nanomaterials may be good candidates for accelerating the egestion of actinides.Herein,we report an amidoxime-grafted covalent organic nanosheet?CON-AO?for in vivo removal of uranyl.The cytotoxicity of CON-AO is at the same level as the only licensed decorporation medicine of DTPA salts,while its uranyl removal ratio in kidney?prompt ip.injection?of 47.3%is much higher than that of ZnNa₃-DTPA?11.4%?.It is of great practical significance for the exploration of efficient and low-toxicity actinide decorporation to provide a basic guarantee for human health and the development of nuclear industry.