pentafluoroethylium | 38664-34-5

• 分子结构分类: 有机化合物 - 有机卤素化合物 - 有机氟化物
• 英文名称: pentafluoroethylium
• 英文别名: 1,1,1,2,2-pentafluoroethane
• CAS: 38664-34-5
• 化学式: C₂F₅
• 分子量: 119.014
• InChiKey: JAUXPHBUDDJEMA-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.98
• 重原子数：
  7.0
• 可旋转键数：
  0.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  pentafluoroethylium 以 gas 为溶剂， 生成 二氟卡宾 、 trifluoromethylium
  参考文献：
  名称：

  快束中多原子离子的单光子红外光解离

  摘要：

  DOI：

  10.1021/j100295a030
• 作为产物：
  描述：

  五氟碘乙烷 生成 pentafluoroethylium
  参考文献：
  名称：

  UV photodissociation of C₂F₅Br, C₂F₅I, and 1,2‐C₂F₄BrI

  摘要：

  The photodissociation reactions of C2F5Br, C2F5I, and 1,2-C2F4BrI have been studied at 248 and 193 nm using the crossed laser-molecular beam technique. Photodissociation of 1,2-C2F4BrI was also studied at 266 nm. We find that: (i) C2F5Br undergoes C–Br bond fission at 193 nm (but does not absorb at 248 nm); (ii) C2F5I undergoes C–I bond fission at 248 nm (but does not absorb at 193 nm); (iii) 1,2-C2F4BrI undergoes only C–I bond fission at 248 and 266 nm, but at 193 nm both C–I and C–Br bond fission are observed, with a C–I:C–Br fission ratio of approximately 1.7:1. Center-of-mass recoil energy and angular distributions are determined for each of these photodissociation reactions. These results combined with those of other workers, are used to test simple predictions based on molecular orbital theory. The 266 nm data for C2F4BrI provide an approximate value of 19.3±3 kcal/mol for the dissociation energy of C2F4Br to C2F4+Br and also show that all or almost all the iodine produced in the primary C–I bond fission is in the excited 2P1/2 state. The prospect of doing bond-selective photochemistry in the ultraviolet is discussed.

  DOI：

  10.1063/1.448056

文献信息

• Study of the Gas Phase Reactions of Several Perfluorocarbons with Positive Ions of Atmospheric Interest
  作者：Gary K. Jarvis、Chris A. Mayhew、Richard P. Tuckett

  DOI：10.1021/jp960071d

  日期：1996.1.1

  studied that reacts with H3O+ at a measurable rate. All the other reactions take place at or close to the collisional rate, the exceptions being the reactions of N2O+ with C2F4 and C3F8, and CO2+ with C2F4 and C2F6, for which the experimental rate coefficients show marked departures from the collisional values. It is proposed that most of the reactions proceed through a complex intermediate resulting

  H 3 O +，NO +，O 2 +，H 2 O +，N 2 O +，O +，CO 2 +，CO +，N +和N 2 +反应的双分子速率系数和离子产物具有三个氟代烯烃（C 2 F 4，C 3 F 6和2-C 4 F 8）和三个完全饱和的全氟化碳（C 2 F 6，C 3 F报道了在300K下的8和n -C 4 F 10）。发现所有六个全氟化碳均与NO +不反应。C 2 F 6也与O 2 +，H 2 O +和N 2 O +不反应，并且C 3 F 8和n -C 4 F 10也与O 2 +不反应。C 3 F 6是唯一与H 3 O +反应的全氟化碳以可测量的速度 所有其他反应均以碰撞速度或接近碰撞速度的方式发生，但N 2 O +与C 2 F 4和C 3 F 8以及CO 2 +与C 2 F 4和C 2 F 6的反应除外。，其实验速率系数显示出与碰撞值的明显偏离。建议大多数反应通过复杂的中间体进行，导致
• Electron-stimulated chemistry of CF₃I adsorbed on Ag(111) C—F bond cleavage and C—C coupling
  作者：Jeffrey E. Fieberg、Andras Szabo、J. M. White

  DOI：10.1039/ft9969204739

  日期：——

  For CF3I adsorbed on Ag(111), reactions stimulated by 100 eV electrons are characterized by temperature programmed desorption (TPD) and reflection–absorption infrared spectroscopy (RAIRS). In the absence of electron irradiation, multilayers desorb at 100 K, two orientations in the first layer desorb at 110 and 128 K, and CF3 radical desorption occurs at 300 K. After electron irradiation of coverages below one layer [θ < 0.30 monolayer (ML)], the remaining parent desorption is broadly distributed between 110 and 225 K, there is a C2F5 radical desorption peak at 340 K and the 300 K CF3 radical desorption is replaced by a peak at 240 K. At coverages greater than 0.30 ML, TPD after electron irradiation reveals two new products (CF2I2 and C2F3I) formed in roughly equal amounts. RAIRS suggests that adsorbed CF2I2 has C2v symmetry with both I atoms bound to Ag. We propose that C—C coupling to form C2F5 occurs by insertion of CF2+ or CF2, formed by impact ionization of the parent, into adsorbed CF3, previously formed during either adsorption or the earlier stages of electron irradiation. CF2I2 formation is described in terms of two possible processes: (i) formation of I–, which reacts with neighbouring CF3I, and (ii) C—F fragmentation of CF3I+, formed in multilayers, into CF2I+, which reacts with previously formed atomic iodine. At 0.75 ML, the cross-section for loss of CF3I by all removal processes is 1.1 ± 0.2 × 10–16 cm2, whereas that for CF2I2 formation is ca. 10–17 cm2.

  对于吸附在 Ag(111) 上的 CF3I，100 eV 电子激发的反应是通过温度编程解吸（TPD）和反射吸收红外光谱（RAIRS）来描述的。在没有电子辐照的情况下，多层在 100 K 时解吸，第一层的两个取向在 110 K 和 128 K 时解吸，CF3 自由基在 300 K 时解吸。当覆盖层大于 0.30 ML 时，电子辐照后的 TPD 显示有两种新产物（CF2I2 和 C2F3I）形成，数量大致相同。RAIRS 表明，吸附的 CF2I2 具有 C2v 对称性，两个 I 原子都与 Ag 结合。我们认为，CâC 耦合形成 C2F5 是通过将母体撞击电离形成的 CF2+ 或 CF2 插入到吸附的 中发生的， 之前是在吸附或电子辐照的早期阶段形成的。CF2I2 的形成有两种可能的过程：(i) Iâ 的形成，它与邻近的 发生反应；(ii) 在多层中形成的 + 的 CâF 断裂成 CF2I+，它与之前形成的原子碘发生反应。在 0.75 ML 条件下，通过所有去除过程损失 的横截面为 1.1 ± 0.2 à 10â16 cm2，而形成 CF2I2 的横截面约为 10â17 cm2。
• Reactions of Ar⁺ with halocarbons and of I⁺ with CF₃I
  作者：Robert A. Morris、Jane M. Van Doren、A. A. Viggiano、John F. Paulson

  DOI：10.1063/1.463605

  日期：1992.7

  The gas phase reactions of Ar+ with the halocarbons CF3Cl, CF3Br, CF3I, CF4, C2F6, and C2F4 have been studied using a variable temperature-selected ion flow tube (VT-SIFT) instrument operated at 298 and 500 K. Rate constants and product branching percentages were measured at both temperatures. Ar+ reacts at the collisional rate with all of the above neutrals at both 298 and 500 K. The reactions with CF3X yield CF+3 and CF2X+ for all X (the reaction with CF4 produces only CF+3 ). For X=I, there is an additional channel leading to the ionic product I+. The reaction of Ar+ with C2F6 produces both CF+3 and C2F+5. The reaction of Ar+ with C2F4 forms a rich product spectrum consisting of the ions CF+, CF+2, CF+3, C2F+3, and C2F+4. The reaction product distributions are compared with results from ionization experiments such as photoion–photoelectron coincidence (PIPECO) and electron impact mass spectrometry, and in some cases excellent agreement is found. The reaction of I+ with CF3I, which is a secondary reaction in the Ar+/CF3I system, was investigated at 298 K in separate experiments. This reaction is rapid and forms four product ions: CF+3, CF2I+, CF3I+, and I+2. The results are compared with previously published information.
• Chemistry of CFn+ (n = 1-3) ions with halocarbons
  作者：Robert A. Morris、A. A. Viggiano、Jane M. Van Doren、John F. Paulson

  DOI：10.1021/j100185a038

  日期：1992.3

  The gas-phase reactions of CF+, CF2+, and CF3+ with the halocarbons CF3Cl, CF3Br, CF3I, CF4, and C2F6 have been studied using a variable-temperature-selected ion flow tube (VT-SIFT) instrument at 300 and 496 K. The ion CF+ reacts rapidly with CF3X (X = Cl, Br, I) producing the ions CF2X+. In the reaction of CF+ with CF3Cl, CF3+ is also produced as a minor product. Curvature was observed in the pseudo-first-order kinetics plots for the reactions of CF+ with CF4 and C2F6. In both cases the curvature is attributed to the presence of two or more CF+ states (probably vibrational) of differing reactivities toward the perfluorocarbon of interest. This conclusion is supported by our observation of charge transfer from CF+ to NO, a reaction which is endothermic by 15 kJ/mol for the ground state of CF+. CF+ is unreactive with O2, N2, and Xe. The reactions of CF2+ with CF3X yield CF3+ and CF2X+ for X = Cl and Br; for X = I, CF2I+ and CF3I+ are produced. The overall reactions proceed at approximately the collision rate at 300 and 496 K, and the branching ratios are not strongly dependent on temperature. The reactions of CF2+ with CF4 and C2F6 produce CF3+ and C2F5+, respectively. The rate constants decrease significantly with increasing temperature. CF2+ reacts rapidly by charge transfer with NO. The reaction of CF2+ with O2, producing CF2O+, is inefficient. CF2+ is unreactive with N2. CF3+ reacts with CF3X (X = Cl, Br, I) at rates below the collision values, producing a single ionic product, CF2X+. While the rate constants for the reactions of CF3+ with CF3X increase in the series with increasing CF3X mass, the rate constants for reaction with each CF3X decrease sharply with increasing temperature. A mechanism is proposed in which the reaction proceeds on a double-well potential energy surface. No reaction was observed for the CF3+/CF4 system. CF3+ appeared to react very slowly with C2F6 and NO, producing C2F5+ and NO+, respectively, but reactions with impurities in the neutral reagents cannot be ruled out as the source of these ions. CF3+ is unreactive with O2 and N2.
• Kinetic energy dependence of the reactions of atomic oxygen(1+) and dioxygenyl ion with tetrafluoromethane and hexafluoroethane
  作者：Ellen R. Fisher、P. B. Armentrout

  DOI：10.1021/j100169a015

  日期：1991.8

  Guided ion beam techniques are used to measure cross sections as a function of kinetic energy for reaction of O+ and O2+ with CF4 and C2F6. The predominant ions formed in these fluorocarbon systems correspond to dissociative charge-transfer reactions, with small amounts of FCO+ and F2CO+ being formed. The thresholds and shapes of dissociative charge-transfer cross sections are explained in terms of vertical ionization to various electronic states of CF4+ and C2F6+. In the O+ reactions, fluoride transfer to form CF3+ in the CF4 system and C2F5+ in the C2F6 system is also observed at thermal energies. The formation of carbon oxyfluoride ions in these systems is postulated to occur by insertion of the oxygen ions into C-F bonds of the fluorocarbon molecules. From the O2+ + CF4 and O+ + C2F6 systems, DELTA-(f)H(F2CO+) is determined. The relationship of these reactions to plasma deposition and etching is discussed.