Journal article
Crystal structure of the uranium oxo borohydride complex U2(μ-O)(BH4)6(dme)2 (dme=1,2-dimethoxyethane) and reformulation of U2(μ-H)2(BH4)6(dme)2
Polyhedron, Vol.33(1), pp.41-44
02/09/2012
DOI: 10.1016/j.poly.2011.11.003
Abstract
The reaction of uranium tetrachloride, UCl4, with sodium N,N-dimethylaminodiboranate, Na(H3BNMe2BH3), in refluxing 1,2-dimethoxyethane (dme) yields a new complex, which we formulate as (μ-oxo)hexakis(tetrahydroborato)bis(1,2-dimethoxyethane)diuranium(IV), toluene solvate, U2(μ-O)(BH4)6(dme)2·C7H8, 1. The crystallographic and 1H NMR data strongly suggest that the previously reported uranium hydride complex U2(μ-H)2(BH4)6(dme)2 should be reformulated as this oxo complex U2(μ-O)(BH4)6(dme)2. [Display omitted] ► UCl4+Na(H3BNMe2BH3) in 1,2-dimethoxyethane yields U2(μ-O)(BH4)6(dme)2·C7H8, 1. ► Formation of BH4− groups from H3BNMe2BH3− occurs with the elimination of [Me2NBH2]2. ► Formation of the oxo group probably involves adventitious hydrolysis. ► The X-ray crystal structure of 1 is reported. ► The previously reported hydride U2(μ-H)2(BH4)6(dme)2 is actually the oxo complex 1. The reaction of uranium tetrachloride, UCl4, with sodium N,N-dimethylaminodiboranate, Na(H3BNMe2BH3), in refluxing 1,2-dimethoxyethane (dme) yields small amounts of a new complex, which we formulate as (μ-oxo)hexakis(tetrahydroborato)bis(1,2-dimethoxyethane)diuranium(IV), toluene solvate, U2(μ-O)(BH4)6(dme)2·C7H8, 1. Most likely, the formation of BH4− groups from H3BNMe2BH3− occurs with the elimination of [Me2NBH2]2, and the formation of the oxo group involves adventitious hydrolysis. Each uranium center in 1 adopts a fac octahedral geometry (counting the BH4− groups as occupying one coordination site); the bridging oxygen atom and the two coordinated oxygen atoms of the dme ligand occupy positions trans to the three BH4− groups. The hydrogen atom positions were located in the electron density difference maps and reveal that all three BH4− groups are bound in a κ3H fashion. The U⋯B distances to the two BH4− groups that are cis to the bridging oxygen atom are 2.574(6) and 2.584(6)Å, whereas the U⋯B distance of 2.635(7)Å to the BH4− group that is trans to the bridging oxygen is distinctly longer. Thus, the bridging oxygen atom exerts a noticeable trans influence. The crystallographic and 1H NMR data strongly suggest that the previously reported uranium hydride complex U2(μ-H)2(BH4)6(dme)2 should be reformulated as this oxo complex U2(μ-O)(BH4)6(dme)2.
Details
- Title: Subtitle
- Crystal structure of the uranium oxo borohydride complex U2(μ-O)(BH4)6(dme)2 (dme=1,2-dimethoxyethane) and reformulation of U2(μ-H)2(BH4)6(dme)2
- Creators
- Scott R Daly - The School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USAMichel Ephritikhine - CEA, IRAMIS, SIS2M, CNRS UMR 3299, 91191 Gif-Sur-Yvette, FranceGregory S Girolami - The School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
- Resource Type
- Journal article
- Publication Details
- Polyhedron, Vol.33(1), pp.41-44
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.poly.2011.11.003
- ISSN
- 0277-5387
- Grant note
- name: National Science Foundation, award: CHE07-50422, DMR-0420768; name: PG Research Foundation; name: George L. Clark X-ray facility; DOI: 10.13039/501100004794, name: Centre National de la Recherche Scientifique; name: Commissariat à l’Energie Atomique
- Language
- English
- Date published
- 02/09/2012
- Academic Unit
- Chemistry
- Record Identifier
- 9983985995102771
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