Copper(I) and Copper(II) Uranyl Heterometallic Hybrid Materials

Abstract

Two copper-uranium heterometallic compounds, [(UO2)3Cu(II)O2(C6NO2)5] (1) and [(UO2)Cu(I)(C6NO2)3] (2), have been synthesized by the reaction of uranyl acetate with copper salts in the presence of isonicotinic acid. Both compounds have been characterized by single-crystal X-ray diffraction, IR, Raman, and UV-vis spectroscopy. In compound 1, interactions between copper and uranium centers occur and result in a three-dimensional pillar layered structure. Compound 1 is also the first example of a heterometallic uranyl organic framework with a trinuclear U3O18 building block. Compound 2 is the first uranyl organic framework that contains monovalent copper, which arises from the reaction of Cu(II) chloride and is assumed to be due to the oxidation of chloride at low pH.

Hydrothermal synthesis, crystal structure and properties of a two-dimensional uranyl coordination polymer based on a flexible zwitterionic ligand

“…) bond lengths range from 2.318 (7) to 2.344 (7) Å , and are much shorter than the U-O(COO À ) bond lengths [2.454 (8) and 2.485 (9) Å ]. The average U-O single-bond length is 2.386 Å , which is consistent with reported values (Weng et al, 2014). In addition, three O atoms in every SO 4 2À anion coordinate to three (UO 2 ) 2+ cations separately.…”

Tubelike Uranyl–Phenylenediacetate Assemblies from Screening of Ligand Isomers and Structure-Directing Counterions

“…Syntheses were attempted in all cases with either N,N-dimethylformamide or acetonitrile cosolvents, one or the other being more successful in each particular case (DMF for 1, 2, 5, and 8-10, and acetonitrile for 3, 4, 6 and 7), for no obvious reason. Only in the case of 5 has the organic solvent a direct bearing on the product formed, as the lattice includes dimethylammonium cations generated in situ from DMF hydrolysis, as frequently observed; in this complex, the Cu II ions originally present have been reduced to Cu I , an occurrence previously encountered,26,45,46 and presumably due to stabilization of the lower oxidation state by bipy ligands. Complex 10 was obtained together with the uranium-only complex [H2NMe2]2[(UO2)2(1,4-PDA)3], which will be presented elsewhere and contains also dimethylammonium cations; unfortunately, replacement of DMF by acetonitrile in this case gave no exploitable crystalline species.…”

An All‐Alkynyl Protected 74‐Nuclei Silver(I)–Copper(I)‐Oxo Nanocluster: Oxo‐Induced Hierarchical Bimetal Aggregation and Anisotropic Surface Ligand Orientation

“…Theb ond-valence sums (BVS) [15] of the Cu centers are consistent with their mono-valence and the typical red color ( Figure S2) also indicates the valence of copper atoms in NC-1. [16] Thet etrahedral Cu 4 moieties supported by inner m 4 -oxo have been previously reported, however all of them are copper(II) ions with oxo ions located at the central of amuch regular Cu 4 tetrahedron and there is no precedent of so many oxo ions trapped in one cluster. [17] There are two sets of three Cu 4 tetrahedra sharing av ertex, and two sets of two Cu 4 tetrahedra sharing one edge,while the left two are independent.…”

“…Of note, one of four Cu−O bonds is always much longer than others, indicating the O 2− atom deviates from the centers of tetrahedron (Table S2). The bond‐valence sums (BVS) of the Cu centers are consistent with their mono‐valence and the typical red color (Figure S2) also indicates the valence of copper atoms in NC‐1 . The tetrahedral Cu 4 moieties supported by inner μ 4 ‐oxo have been previously reported, however all of them are copper(II) ions with oxo ions located at the central of a much regular Cu 4 tetrahedron and there is no precedent of so many oxo ions trapped in one cluster .…”