Solid-State NMR Spectroscopic Study of Coordination Compounds of XeF2 with Metal Cations and the Crystal Structure of [Ba(XeF2)5][AsF6]2
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- 作者：Michael Gerken ; Paul Hazendonk ; Adriana Iuga ; Jared Nieboer ; Melita Tram<img src="http ; //pubs.acs.org/images/entities/scaron.gif" border="0">ek ; Evgeny Goreshnik ; Boris <img src="http ; //pubs.acs.org/i
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：July 23, 2007
- 年：2007
- 卷：46
- 期：15
- 页码：6069 - 6077
- 全文大小：195K
- 年卷期：v.46,no.15(July 23, 2007)
- ISSN：1520-510X
文摘
The coordination compounds [Mg(XeF2)2][AsF6]2, [Mg(XeF2)4][AsF6]2, [Ca(XeF2)2.5][AsF6]2, [Ba(XeF2)3][AsF6]2, and[Ba(XeF2)5][AsF6]2 were characterized by solid-state 19F and 129Xe magic-angle spinning NMR spectroscopy. The19F and 129Xe NMR data of [Mg(XeF2)2][AsF6]2, [Mg(XeF2)4][AsF6]2, and [Ca(XeF2)2.5][AsF6]2 were correlated withthe previously determined crystal structures. The isotropic 19F chemical shifts and 1J(129Xe-19F) coupling constantswere used to distinguish the terminal and bridging coordination modes of XeF2. Chemical-shift and coupling-constant calculations for [Mg(XeF2)4][AsF6]2 confirmed the assignment of terminal and bridging chemical-shift andcoupling-constant ranges. The NMR spectroscopic data of [Ba(XeF2)3][AsF6]2 and [Ba(XeF2)5][AsF6]2 indicate theabsence of any terminal XeF2 ligands, which was verified for [Ba(XeF2)5][AsF6]2 by its X-ray crystal structure. Theadduct [Ba(XeF2)5][AsF6]2 crystallizes in the space group Fmmm, with a = 11.6604(14) Å, b = 13.658(2) Å, c =13.7802(17) Å, V = 2194.5(5) Å3 at -73 <IMG SRC="/images/entities/deg.gif">C, Z = 4, and R = 0.0350 and contains two crystallographicallyindependent bridging XeF2 molecules and one nonligating XeF2 molecule. The AsF6- anions in [Mg(XeF2)4][AsF6]2,[Ca(XeF2)2.5][AsF6]2, [Ba(XeF2)3][AsF6]2, and [Ba(XeF2)5][AsF6]2 were shown to be fluxional with the fluorines-on-arsenic being equivalent on the NMR time scale, emulating perfectly octahedral anion symmetry.