Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
Inorg Chem. 2010 Apr 5;49(7):3501-15. doi: 10.1021/ic100062x.
Stoichiometric amounts of XeF(6) and (OsO(3)F(2))(infinity) react at 25-50 degrees C to form salts of the known XeF(5)(+) and Xe(2)F(11)(+) cations, namely, [XeF(5)][mu-F(OsO(3)F(2))(2)], [XeF(5)][OsO(3)F(3)], and [Xe(2)F(11)][OsO(3)F(3)]. Although XeF(6) is oxophilic toward a number of transition metal and main-group oxides and oxide fluorides, fluoride/oxide metathesis was not observed. The series provides the first examples of noble-gas cations that are stabilized by metal oxide fluoride anions and the first example of a mu-F(OsO(3)F(2))(2)(-) salt. Both [XeF(5)][mu-F(OsO(3)F(2))(2)] and [Xe(2)F(11)][OsO(3)F(3)] are orange solids at room temperature. The [XeF(5)][OsO(3)F(3)] salt is an orange liquid at room temperature that solidifies at 5-0 degrees C. When the salts are heated at 50 degrees C under 1 atm of N(2) for more than 2 h, significant XeF(6) loss occurs. The X-ray crystal structures (-173 degrees C) show that the salts exist as discrete ion pairs and that the osmium coordination spheres in OsO(3)F(3)(-) and mu-F(OsO(3)F(2))(2)(-) are pseudo-octahedral OsO(3)F(3)-units having facial arrangements of oxygen and fluorine atoms. The mu-F(OsO(3)F(2))(2)(-) anion is comprised of two symmetry-related OsO(3)F(2)-groups that are fluorine-bridged to one another. Ion pairing results from secondary bonding interactions between the fluorine/oxygen atoms of the anions and the xenon atom of the cation, with the Xe...F/O contacts occurring opposite the axial fluorine and from beneath the equatorial XeF(4)-planes of the XeF(5)(+) and Xe(2)F(11)(+) cations so as to avoid the free valence electron lone pairs of the xenon atoms. The xenon atoms of [XeF(5)][mu-F(OsO(3)F(2))(2)] and [Xe(2)F(11)][OsO(3)F(3)] are nine-coordinate and the xenon atom of [XeF(5)][OsO(3)F(3)] is eight-coordinate. Quantum-chemical calculations at SVWN and B3LYP levels of theory were used to obtain the gas-phase geometries, vibrational frequencies, and NBO bond orders, valencies, and NPA charges of the ion pairs, [Xe(2)F(11)][OsO(3)F(3)], [XeF(5)][OsO(3)F(3)], and [XeF(5)][mu-F(OsO(3)F(2))(2)], as well as those of the free ions, Xe(2)F(11)(+), XeF(5)(+), OsO(3)F(3)(-), and mu-F(OsO(3)F(2))(2)(-). The Raman spectra (-150 degrees C) of the salts have been assigned based on the ion pairs observed in the crystal structures and the calculated vibrational frequencies and intensities of the gas-phase ion pairs.
氙六氟化物（XeF6）与（OsO3F2）（无穷）以化学计量比在 25-50°C 下反应，形成已知的 XeF5(+)和 Xe2F11(+)阳离子的盐，即[XeF5][μ-F(OsO3F2)]（2）]，[XeF5][OsO3F3]和[Xe2F11][OsO3F3]。尽管 XeF6 对许多过渡金属和主族氧化物和氧化物氟化物具有亲氧性，但未观察到氟化物/氧化物交换反应。该系列提供了第一个由金属氧化物氟化物阴离子稳定的稀有气体阳离子的例子，也是第一个μ-F(OsO3F2)]（2）盐的例子。室温下，[XeF5][μ-F(OsO3F2)]（2）]和[Xe2F11][OsO3F3]均为橙色固体。室温下[XeF5][OsO3F3]盐为橙色液体，在 5-0°C 时凝固。当盐在 50°C 下在 1 大气压的 N2 中加热超过 2 小时时，会发生显着的 XeF6 损失。X 射线晶体结构（-173°C）表明盐以离散的离子对形式存在，并且 OsO3F3]-和μ-F(OsO3F2)]（2）中的锇配位球在 OsO3F3]-单元中具有面式排列的氧和氟原子，具有伪八面体结构。μ-F(OsO3F2)]（2）阴离子由两个对称相关的 OsO3F2]-基团组成，彼此通过氟桥连接。离子对是由于阴离子的氟/氧原子与阳离子的氙原子之间的次级键相互作用而形成的，Xe...F/O 接触发生在轴向氟的对面，并且在 XeF5(+)和 Xe2F11(+)阳离子的赤道 XeF4-平面下方，以避免氙原子的自由价电子孤对。[XeF5][μ-F(OsO3F2)]（2）]和[Xe2F11][OsO3F3]的氙原子是九配位的，[XeF5][OsO3F3]的氙原子是八配位的。使用 SVWN 和 B3LYP 理论水平的量子化学计算获得了气相几何形状、振动频率和 NBO 键序、价态和 NPA 电荷的离子对[Xe2F11][OsO3F3]、[XeF5][OsO3F3]和[XeF5][μ-F(OsO3F2)]（2）]以及游离离子 Xe2F11(+)、XeF5(+)、OsO3F3]-和μ-F(OsO3F2)]（2）的自由离子。根据晶体结构中观察到的离子对以及气相离子对的计算振动频率和强度，对盐的拉曼光谱（-150°C）进行了分配。
