Tetramethylammonium difluorophosphate

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 有机磷酸及其衍生物
• 英文名称: Tetramethylammonium difluorophosphate
• 英文别名: Difluorophosphinate;tetramethylazanium；difluorophosphinate;tetramethylazanium
• 化学式: C₄H₁₂N*F₂O₂P
• 分子量: 175.115
• InChiKey: XYWNEQDHHLUNFD-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  0.72
• 重原子数：
  10
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  40.1
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  磷酰氟 、 四甲基氟化铵 以 neat (no solvent) 为溶剂， 生成 Tetramethylammonium difluorophosphate 、 tetramethylammonium hexafluorophosphate
  参考文献：
  名称：

  Tetrafluorophosphate Anion

  摘要：

  The elusive POF4- anion has been characterized for the first time. It is formed from N(CH3)(4)F and POF3 in CHF3 solution at -140 degrees C and can be observed at this temperature by F-19 and P-31 NMR spectroscopy. Between -140 and -100 degrees C it reacts with POS forming the OF2P-O-PF5- anion, which, at higher temperatures, reacts with F- anions to give PO2F2- and PF6-. This reaction sequence provides a low activation energy barrier pathway for the highly exothermic dismutation of pseudo-trigonal-bipyramidal POF4- to tetrahedral PO2F2- and octahedral PF6- and explains the previous failures to isolate POF4- salts. In addition to POF4-, OF2POPF5-, and PO2F2-, the protonated form of OF2POPF5-, i.e., HOF2POPF5, was also identified as a byproduct by NMR spectroscopy. The structure, vibrational spectra, force field, NMR parameters, and dismutation energy of POF4- were calculated by nb initio electronic structure methods using, where required, the closely related and well-known PF4- ion and POF3, PF3, SOF4, and SF4 molecules for the determination of scaling factors. Although the structures and dismutation energies of isoelectronic POF4- and SOF4 are very similar, their dismutation behavior is strikingly different. While POF4- dismutates rapidly at low temperatures, SOF4 is kinetically stable toward dismutation to SO2F2 and SF6. This fact is attributed to the lack of a low activation energy barrier pathway for SOF(4)7. Furthermore, the dismutation energy calculations for POF4-, SOF4, and ClOF3 revealed very large errors in the previously published thermodynamic data for the heats of formations of SO2F2 and SOF4 and the dismutation reaction energy of POF4-. Energy barriers and the C-4v transition states for the Berry-style pseudorotational exchange of equatorial and axial fluorines in POF4-, SOF4, PF4-, and SF4 were also calculated and can account for the observation that on the NMR time scale the exchange in PF4- and SF4 can be frozen out at about -40 degrees C, while in POF4- and SOF4 it is still rapid at -140 and -150 degrees C, respectively.

  DOI：

  10.1021/ja963421i

文献信息

• New Anions of Pentacoordinate Phosphorus Containing Fluorine and Trifluoromethyl Groups
  作者：Natalya V. Pavlenko、Lesya A. Babadzhanova、Igor I. Gerus、Yurii L. Yagupolskii、Wieland Tyrra、Dieter Naumann

  DOI：10.1002/ejic.200600974

  日期：2007.4

  (PhO)3P(O), Me3SiCF3 and the fluoride ion sources [Me4N]F and CsF, respectively, in glyme. These anions represent the stable transition states postulated for nucleophilic substitution at a tetrahedral phosphorus atom. The salt Cs[(CF3)2PF2O] (7) is stable at room temperature for a month, while [Me4N][CF3PF3O] (1) dismutates into [Me4N][CF3PF(O)O] (2) and [Me4N][CF3PF5] (3) above 0 °C. (© Wiley-VCH Verlag

  首次获得并表征了独特的伪三角双锥体 CF3PF3O– 和 (CF3)2PF2O– 阴离子。它们分别由 (PhO)3P(O)、Me3SiCF3 和氟离子源 [Me4N]F 和 CsF 在甘醇二甲醚中反应形成。这些阴离子代表在四面体磷原子处亲核取代所假定的稳定过渡态。盐 Cs[(CF3)2PF2O] (7) 在室温下稳定一个月，而 [Me4N][CF3PF3O] (1) 歧化为 [Me4N][CF3PF(O)O] (2) 和 [Me4N] [CF3PF5] (3) 高于 0 °C。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
• Tetrafluorophosphate Anion
  作者：Karl O. Christe、David A. Dixon、Gary J. Schrobilgen、William W. Wilson

  DOI：10.1021/ja963421i

  日期：1997.4.1

  The elusive POF4- anion has been characterized for the first time. It is formed from N(CH3)(4)F and POF3 in CHF3 solution at -140 degrees C and can be observed at this temperature by F-19 and P-31 NMR spectroscopy. Between -140 and -100 degrees C it reacts with POS forming the OF2P-O-PF5- anion, which, at higher temperatures, reacts with F- anions to give PO2F2- and PF6-. This reaction sequence provides a low activation energy barrier pathway for the highly exothermic dismutation of pseudo-trigonal-bipyramidal POF4- to tetrahedral PO2F2- and octahedral PF6- and explains the previous failures to isolate POF4- salts. In addition to POF4-, OF2POPF5-, and PO2F2-, the protonated form of OF2POPF5-, i.e., HOF2POPF5, was also identified as a byproduct by NMR spectroscopy. The structure, vibrational spectra, force field, NMR parameters, and dismutation energy of POF4- were calculated by nb initio electronic structure methods using, where required, the closely related and well-known PF4- ion and POF3, PF3, SOF4, and SF4 molecules for the determination of scaling factors. Although the structures and dismutation energies of isoelectronic POF4- and SOF4 are very similar, their dismutation behavior is strikingly different. While POF4- dismutates rapidly at low temperatures, SOF4 is kinetically stable toward dismutation to SO2F2 and SF6. This fact is attributed to the lack of a low activation energy barrier pathway for SOF(4)7. Furthermore, the dismutation energy calculations for POF4-, SOF4, and ClOF3 revealed very large errors in the previously published thermodynamic data for the heats of formations of SO2F2 and SOF4 and the dismutation reaction energy of POF4-. Energy barriers and the C-4v transition states for the Berry-style pseudorotational exchange of equatorial and axial fluorines in POF4-, SOF4, PF4-, and SF4 were also calculated and can account for the observation that on the NMR time scale the exchange in PF4- and SF4 can be frozen out at about -40 degrees C, while in POF4- and SOF4 it is still rapid at -140 and -150 degrees C, respectively.