Journal article
f-Element complexes with benzyl and cyclohexyl substituted trihydroborates
Polyhedron, Vol.269, 117408
03/01/2025
DOI: 10.1016/j.poly.2025.117408
Abstract
[Display omitted]
Actinide complexes containing the simplest borohydrides (BH4)1− and (MeBH3)1− can exhibit remarkably highly volatility, which creates unique hazards and handling challenges, especially when making measurements on solid samples under vacuum. Here we describe efforts to prepare new actinide borohydride complexes with attenuated volatility by adding bulkier benzyl (Bn) and cyclohexyl (Cy) substituents to boron. Reactions of ThCl4, UI3(thf)4, and NdI3 with the mixed alkali metal salt Li/K(BnBH3)(thf)n yielded Th(BnBH3)4(thf)2, U(BnBH3)4(thf)2, and K[Nd(BnBH3)4], respectively. Notable amongst these, the reaction with UI3(thf)4 proceeds via oxidation of U(III) to U(IV) despite the presence of reducing borohydride ligands. Similarly, reactions of the same metal halides with four equivalents of Li(CyBH3)(Et2O)n yielded Th(CyBH3)4, U(CyBH3)4(thf)2, and [Li(Et2O)3][Nd(CyBH3)4]. Single crystal X-ray diffraction studies of the M(BnBH3)4(thf)2 complexes with M = Th and U confirmed their formulations. The complexes have approximate D2d point group symmetry and adopt bicapped hexagonal antiprismatic coordination geometries with axial thf ligands and κ3-BnBH3 ligands bound in the equatorial plane. K[Nd(BnBH3)4] and [Li(Et2O)3][Nd(CyBH3)4], which were prepared for comparison to U(III) complexes that were unsuccessfully targeted, were also structurally characterized to reveal complex anions with tetrahedral arrangements of trihydroborate ligands bound to Nd(III). Crystals obtained for Th(CyBH3)4 and U(CyBH3)4(thf)2 were not suitable for XRD studies, but 1H and 11B NMR spectra were consistent with their formulations. Collectively, these complexes represent rare examples of structurally characterized f-element trihydroborate complexes with carbon substituents other than methyl.
Details
- Title: Subtitle
- f-Element complexes with benzyl and cyclohexyl substituted trihydroborates
- Creators
- Joshua C. Zgrabik - University of IowaPeter A. Zacher - University of IowaScott R. Daly - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Polyhedron, Vol.269, 117408
- DOI
- 10.1016/j.poly.2025.117408
- ISSN
- 0277-5387
- eISSN
- 1873-3719
- Publisher
- Elsevier Ltd
- Grant note
- Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory: 20220518MFR NNSA: DE-NA0004151 NSF: CHE-1828117, CHE-2017828
Research presented in this manuscript was initiated with support by the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory under project number 20220518MFR and completed with funding from the NNSA (DE-NA0004151) . We thank Daniel Unruh for collecting the single-crystal X-ray diffraction (XRD) data. XRD data were collected using the instrument supported by NSF CHE-1828117. Some of the NMR data were collected using the instrument supported by NSF CHE-2017828. We thank Lou Messerle for the gift of ThCl4 .
- Language
- English
- Electronic publication date
- 01/24/2025
- Date published
- 03/01/2025
- Academic Unit
- Chemistry
- Record Identifier
- 9984775013002771
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