Unprecedented pairs of uranium (IV/V) hydroxido and (IV/V/VI) oxido complexes supported by a seven- coordinate cyclen-anchored tris-aryloxide ligand

Löffler S, Hümmer J, Scheurer A, Heinemann FW, Meyer K (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Chemical Science Royal Society of Chemistry

Abstract

We present the synthesis and reactivity of a newly developed, cyclen-based tris-aryloxide ligand precursor, ,- namely cyclen(Me)(t-Bu,t-BuArOH)(3), and its coordination chemistry to uranium. The corresponding uranium(III) complex [U-III((OArt-Bu,t-Bu)(3)(Me)cyclen)] (1) was characterized by H-1 NMR analysis, CHN elemental analysis and UV/vis/NIR electronic absorption spectroscopy. Since no single-crystals suitable for X-ray diffraction analysis could be obtained from this precursor, 1 was oxidized with methylene chloride or silver fluoride to yield [(cyclen(Me)(t-Bu,t-BuArOH)(3))U-IV(X)] (X = Cl (2), F (3)), which were unambiguously characterized and successfully crystallized to gain insight into the molecular structure by single-crystal X-ray diffraction analysis (SC-XRD). Further, the activation of H2O and N2O by 1 is presented, resulting in the U(IV) complex [(cyclen(Me)(t-Bu,t-BuArOH)(3)))U-IV(OH)] (4) and the U(V) complex Rcyclen(Me)(t-Bu,t-BuArOH)(3))U-IV(O)] (6). Complexes 2, 3, 4, and 6 were characterized by H-1 NMR analysis, CHN elemental analysis, UV/vis/NIR electronic absorption spectroscopy, IR vibrational spectroscopy, and SQUID magnetization measurements as well as cyclic voltammetry. Furthermore, chemical oxidation of 3, 4, and 6 with AgF or AgSbF6 was achieved leading to complexes Rcyclen(Me)(t-Bu,t-BuArOH)(3))U-V(F)(2)] (5), Rcyclen(Me)(t-Bu,t-BuArOH)(3))U-V(OH)][SbF6] (7), and Rcyclen(Me)(t-Bu,t-BuArOH)(3))U-V(O)][SbF6] (8). Finally, reduction of 7 with KC8 yielded a U(IV) complex, spectroscopically and magnetochemically identified as K [(cyclen(Me)(t-Bu,t-BuArOH)(3))U-IV(O)].

Authors with CRIS profile

Sascha Löffler Lehrstuhl für Anorganische und Allgemeine Chemie Julian Hümmer Lehrstuhl für Anorganische und Allgemeine Chemie Andreas Scheurer Lehrstuhl für Anorganische und Allgemeine Chemie Frank Wilhelm Heinemann Lehrstuhl für Anorganische und Allgemeine Chemie Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie

How to cite

APA:

Löffler, S., Hümmer, J., Scheurer, A., Heinemann, F.W., & Meyer, K. (2022). Unprecedented pairs of uranium (IV/V) hydroxido and (IV/V/VI) oxido complexes supported by a seven- coordinate cyclen-anchored tris-aryloxide ligand. Chemical Science. https://doi.org/10.1039/d2sc02736d

MLA:

Löffler, Sascha, et al. "Unprecedented pairs of uranium (IV/V) hydroxido and (IV/V/VI) oxido complexes supported by a seven- coordinate cyclen-anchored tris-aryloxide ligand." Chemical Science (2022).

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