F5SN(H)Xe+; a Rare Example of Xenon Bonded to sp3-Hybridized Nitrogen; Synthesis and Structural Characterization of [F5SN(H)Xe][AsF6]
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- 作者：Gregory L. Smith ; Hé ; lè ; ne P. A. Mercier ; Gary J. Schrobilgen
- 刊名：Inorganic Chemistry
- 出版年：2008
- 出版时间：May 19, 2008
- 年：2008
- 卷：47
- 期：10
- 页码：4173 - 4184
- 全文大小：1089K
- 年卷期：v.47,no.10(May 19, 2008)
- ISSN：1520-510X
文摘
The salt [F5SN(H)Xe][AsF6] has been synthesized by the reaction of [F5SNH3][AsF6] with XeF2 in anhydrous HF (aHF) and BrF5 solvents and by solvolysis of [F3S
d1.gif">NXeF][AsF6] in aHF. Both F5SN(H)Xe+ and F5SNH3+ have been characterized by 129Xe, 19F, and 1H NMR spectroscopy in aHF (−20 °C) and BrF5 (supercooled to −70 °C). The yellow [F5SN(H)Xe][AsF6] salt was crystallized from aHF at −20 °C and characterized by Raman spectroscopy at −45 °C and by single-crystal X-ray diffraction at −173 °C. The Xe−N bond length (2.069(4) Å) of the F5SN(H)Xe+ cation is among the shortest Xe−N bonds presently known. The cation interacts with the AsF6− anion by means of a Xe---F−As bridge in which the Xe---F distance (2.634(3) Å) is significantly less than the sum of the Xe and F van der Waals radii (3.63 Å) and the AsF6− anion is significantly distorted from Oh symmetry. The 19F and 129Xe NMR spectra established that the [F5SN(H)Xe][AsF6] ion pair is dissociated in aHF and BrF5 solvents. The F5SN(H)Xe+ cation decomposes by HF solvolysis to F5SNH3+ and XeF2, followed by solvolysis of F5SNH3+ to SF6 and NH4+. A minor decomposition channel leads to small quantities of F5SNF2. The colorless salt, [F5SNH3][AsF6], was synthesized by the HF solvolysis of F3Sd1.gif">NAsF5 and was crystallized from aHF at −35 °C. The salt was characterized by Raman spectroscopy at −160 °C, and its unit cell parameters were determined by low-temperature X-ray diffraction. Electronic structure calculations using MP2 and DFT methods were used to calculate the gas-phase geometries, charges, bond orders, and valencies as well as the vibrational frequencies of F5SNH3+ and F5SN(H)Xe+ and to aid in the assignment of their experimental vibrational frequencies. In addition to F5TeN(H)Xe+, the F5SN(H)Xe+ cation provides the only other example of xenon bonded to an sp3-hybridized nitrogen center that has been synthesized and structurally characterized. These cations represent the strongest Xe−N bonds that are presently known.
d1.gif">NXeF][AsF6] in aHF. Both F5SN(H)Xe+ and F5SNH3+ have been characterized by 129Xe, 19F, and 1H NMR spectroscopy in aHF (−20 °C) and BrF5 (supercooled to −70 °C). The yellow [F5SN(H)Xe][AsF6] salt was crystallized from aHF at −20 °C and characterized by Raman spectroscopy at −45 °C and by single-crystal X-ray diffraction at −173 °C. The Xe−N bond length (2.069(4) Å) of the F5SN(H)Xe+ cation is among the shortest Xe−N bonds presently known. The cation interacts with the AsF6− anion by means of a Xe---F−As bridge in which the Xe---F distance (2.634(3) Å) is significantly less than the sum of the Xe and F van der Waals radii (3.63 Å) and the AsF6− anion is significantly distorted from Oh symmetry. The 19F and 129Xe NMR spectra established that the [F5SN(H)Xe][AsF6] ion pair is dissociated in aHF and BrF5 solvents. The F5SN(H)Xe+ cation decomposes by HF solvolysis to F5SNH3+ and XeF2, followed by solvolysis of F5SNH3+ to SF6 and NH4+. A minor decomposition channel leads to small quantities of F5SNF2. The colorless salt, [F5SNH3][AsF6], was synthesized by the HF solvolysis of F3Sd1.gif">NAsF5 and was crystallized from aHF at −35 °C. The salt was characterized by Raman spectroscopy at −160 °C, and its unit cell parameters were determined by low-temperature X-ray diffraction. Electronic structure calculations using MP2 and DFT methods were used to calculate the gas-phase geometries, charges, bond orders, and valencies as well as the vibrational frequencies of F5SNH3+ and F5SN(H)Xe+ and to aid in the assignment of their experimental vibrational frequencies. In addition to F5TeN(H)Xe+, the F5SN(H)Xe+ cation provides the only other example of xenon bonded to an sp3-hybridized nitrogen center that has been synthesized and structurally characterized. These cations represent the strongest Xe−N bonds that are presently known.