Tetrahydrosalen Uranyl(VI) Complexes: Crystal Structures and Solution Binding Study

Abstract

A pair of uranyl complexes incorporating tetrahydrosalen and N,N-dimethyltetrahydrosalen ligands are synthesized and studied. These new ligands, with saturated secondary and tertiary amines, exhibit higher chemostability than the prototype Schiff base (salen) structure, especially under acidic conditions. As shown by X-ray diffraction crystallography, the coordination geometry of uranium in these new complexes is a distorted pentagonal bipyramid. Interestingly, UO 2 ([H 4 ]salen), comprising the tetrahydrosalen ligand, forms a dimeric structure in the crystals, with two subunits held together by [a]

The Effect of Guest Metal Ions on the Reduction Potentials of Uranium(VI) Complexes: Experimental and Theoretical Investigations

“…[21][22][23][24][25][26][27] The studies of these properties of uranium are helpful for waste managementi nn uclear reactors to prevent water and soil pollution.Uranium forms stable com-plexes with multidentate organic ligands, af act that is exploited in the detection and separation of uranium from nuclear slag, ground water,a nd seawater. [32][33][34][35][36][37][38][39] Ac onvenient method for the synthesis of U V compounds is to reduce the corresponding U VI speciese lectrochemically. [32][33][34][35][36][37][38][39] Ac onvenient method for the synthesis of U V compounds is to reduce the corresponding U VI speciese lectrochemically.…”

“…[28][29][30][31] It shows multiple oxidation states, varying from + III to + VI;h owever,i na erobic conditions the commono xidation state is + VI, which is stabilized as the uranyl dication (UO 2 2 + ). [32][33][34][35][36][37][38][39] Ac onvenient method for the synthesis of U V compounds is to reduce the corresponding U VI speciese lectrochemically. [40][41][42][43] Severalc omplexes of U V with N 2 O 2 donor salen-type Schiff bases have been prepared by this method.…”

“…Uranium forms stable complexes with multidentate organic ligands, a fact that is exploited in the detection and separation of uranium from nuclear slag, ground water, and seawater . It shows multiple oxidation states, varying from +III to +VI; however, in aerobic conditions the common oxidation state is +VI, which is stabilized as the uranyl dication (UO 2 2+ ) . A convenient method for the synthesis of U V compounds is to reduce the corresponding U VI species electrochemically .…”

Chiral Diuranyl(VI) Complexes and Their Catecholase Activities: Experimental and Theoretical Insights

“…A strong band appeared in the range 1605–1620 cm −1 for all the complexes is attributed to the metal coordinated C=N [10c,12a,c,e,f,13a,c,16] . All four spectra display the typical very strong band at ∼894 cm −1 due to the asymmetric stretching vibration of the trans ‐uranyl(VI) moiety [10a,c,12a,c–f] …”

Polymer Nanorings with Uranium Specific Clefts for Selective Recovery of Uranium from Acidic Effluents via Reductive Adsorption

“…Literature reports argue in favor of the adsorption-based scavenging material as the preferred methodology for UO 2 2+ extraction and enrichment, rather than solvent extraction-based processes. − Based on the higher affinity of UO 2 2+ , adsorbents are typically derived using amidoxime, amide, imidazole, organophosphorus, and calixarene, phosphonic acid/phosphazene derivatives for developing a reasonably efficient scavenger for UO 2 2+ . − Such efforts include the use of appropriately functionalized porous organic polymers/COFs, mesoporous carbons, nanostructured or MOF-based materials. ,− Long equilibration time, uncertainty about the influences of nanoparticle on human physiology, and the recent environmental concern of the treated organic/inorganic polymeric materials have limited the use of these reagents/materials for any practical application. Further, the use of any scavenger having a biodegradable polymer has rarely been attempted.…”