bromodifluoromethyl | 28882-09-9

• 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: bromodifluoromethyl
• 英文别名: bromo-difluoro-methyl；Bromodifluoromethyl radical
• CAS: 28882-09-9
• 化学式: CBrF₂
• 分子量: 129.912
• InChiKey: GYOLCDNHOFVAAM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  4
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  bromodifluoromethyl 生成 1,1,2,2-四氟-1,2-二溴乙烷
  参考文献：
  名称：

  CF2Br2 在 248 nm 处的光解：时间分辨吸收研究

  摘要：

  已经使用时间分辨光吸收光谱在气相中研究了 248 nm 处 CF2Br2 的光解。观察到 200-320 nm 范围内的瞬态吸收光谱，λmax ≈ 260 nm，并被指定为主要的光解产物，CF2Br 自由基。已发现该自由基在 260 nm 处的吸收截面为 (1.05 ± 0.2) × 10−18 cm2 分子−1。CF2Br 二聚的速率常数估计为 (3.0 ± 0.6) × 10−12 cm3 分子−1 s−1。讨论了 CF2Br 自由基二次光解中的激光能量密度依赖性。

  DOI：

  10.1246/bcsj.68.2817
• 作为产物：
  描述：

  二氟溴甲烷 在 盐酸 作用下， 21.84 ℃ 、199.98 Pa 条件下， 生成 bromodifluoromethyl
  参考文献：
  名称：

  通过Cl原子共振荧光测量氯原子与CHF 2 Br之间反应的速率常数

  摘要：

  Cl原子与CHF 2 Br之间反应的速率常数已通过在流动反应器中295-368 K的温度和约1.5 Torr的压力下的氯原子共振荧光测量。用F-32L氟塑料衬里反应器的内表面使氯原子的异质损失率非常低（k het≤5 s –1）。反应的速率常数由以下公式给出：k =（4.23±0.13）×10 –12 e （–15.56±1.58）/ RT cm 3分子–1 s –1（活化能以kJ / mol为单位）。讨论了该反应在扑灭产生高浓度氯原子的火中的可能作用。

  DOI：

  10.1134/s0023158416030101

文献信息

• Free radical addition to olefins. Part 5.—Addition of difluorobromomethyl radicals to trifluoroethylene and ethylene
  作者：J. M. Tedder、J. C. Walton

  DOI：10.1039/tf9706601135

  日期：——

  The photochemical reaction of CF2Br2 with CHFCF2 and CH2CH2 has been examined in a series of gas-phase experiments. A mechanism for the radical chain addition which takes place is proposed. The variation in the rate of formation of the termination products, CF2BrCF2Br and CF2BrCHFCF2Br, with reactant concentration is explained if five important termination reactions are taken into account and a long-lived excited state of the CF2Br2 is accepted. Arrhenius parameters for the addition of CF2Br· radicals to the olefins have been derived : CF2Br·+ E → CF2BrE·(2), CF2Br·+ CF2Br·→ CF2BrCF2Br (4), k2/k½4(addition to CHF)=(1.2 ± 0.3)× 102 exp (–3300 ± 200/RT), k2/k½4(addition to CF2)=(2.0 ± 0.3)× 102 exp (–4400 ± 200/RT), k2/k½4(addition to CH2)=(2.5 ± 0.5) exp (–1000/RT). A factors are in 1.½ mol–½ s–½; activation energies in kcal/mol; R= 1.99 cal deg.–1 mol–1; 1 cal = 4.184 J.

  通过一系列气相实验研究了 CF2Br2 与 CHFCF2 和 CH2CH2 的光化学反应。提出了发生自由基链加成反应的机理。如果考虑到五个重要的终止反应，并接受 CF2Br2 的长寿命激发态，就可以解释终止产物 CF2BrCF2Br 和 CF2BrCHFCF2Br 的形成速率随反应物浓度的变化。得出了 CF2BrÂ-自由基与烯烃加成的阿伦尼乌斯参数：CF2BrÂ-+ Eâ CF2BrEÂ-(2), CF2BrÂ-+ CF2BrÂ-â CF2BrCF2Br (4), k2/k½4（与 CHF 的加成）=(1.2 ± 0.3)à 102 exp (â3300 ± 200/RT)，k2/k½4(加入CF2)=(2.0 ± 0.3)à 102 exp (â4400 ± 200/RT)，k2/k½4(加入CH2)=(2.5 ± 0.5) exp (â1000/RT)。A 系数单位为 1.½ molâ½ sâ½；活化能单位为 kcal/mol；R= 1.99 cal deg.â1 molâ1；1 cal = 4.184 J。
• Laser (248 nm) Flash Photolysis and Pulse Radiolysis of CF₂Br₂in Aqueous Solution: Atmospheric Implications
  作者：Rameshwar D. Saini、Suresh Dhanya、Tomi Nath Das

  DOI：10.1246/bcsj.75.1699

  日期：2002.8

  state as well as laser (248 nm) flash photolysis of CF2Br2 was carried out in aqueous solution. The formation of Br2•− radicals involving two primary photodissociation channels was observed in the flash photolysis. One channel produced CF2Br• and Br• radicals, and the other led to the formation of Br− and H+. The spectrum and reactions of CF2Br• were studied in aqueous solution by pulse radiolysis. The

  在室温下测得 CF2Br2 的亨利定律常数 (Kh) 为 0.058 M atm-1。CF2Br2 的稳态和激光（248 nm）闪光光解在水溶液中进行。在闪光光解中观察到涉及两个主要光解通道的 Br2•- 自由基的形成。一个通道产生 CF2Br• 和 Br• 自由基，另一个导致形成 Br− 和 H+。通过脉冲辐解研究了CF2Br•在水溶液中的光谱和反应。发现 CF2Br• 自由基在 230-270 nm 区域吸收，在 λmax = 245 nm 处的摩尔吸光度 (e) 为 710 M-1 cm-1。某些反应的速率常数在 299 K 下测量如下：k (eaq− + CF2Br2) = 1.20 ± 0.13 × 1010, 2k (CF2Br• + CF2Br•) = 1.4 ± 0.4 × 109, k(CF2Br• + O2) = 1.9 ± 0.5 × 109 M−1 s−1。CF2BrO2•
• Photodissociation dynamics of the reaction CF2Br2+hν→CF2+ 2Br. Energetics, threshold and nascent CF2 energy distributions for λ=223–260 nm
  作者：Melanie R. Cameron、Stephen A. Johns、Gregory F. Metha、Scott H. Kable

  DOI：10.1039/b000203h

  日期：——

  The dissociation dynamics of the reaction CF2Br2+hν→CF2+2 Br have been studied for a variety of dissociation energies, Ediss=460–535 kJ mol−1 (corresponding to λ=260–223 nm). The laser induced fluorescence spectrum of nascent CF2 products was measured for various dissociation energies within this range. Analysis of the spectra yielded the CF2 vibrational distribution and average rotational energy. The translational energy of CF2 was measured ia the Doppler broadening of various fully resolved rovibronic transitions. The most detailed analysis of energy disposal in the CF2 fragments was carried out at Ediss=486 kJ mol−1 (or λ=246 nm). At this energy each degree of freedom of CF2 had an average energy of Evib=0.4±0.2 kJ mol−1, Erot=2.5±0.5 kJ mol−1, and Etrans=24±3 kJ mol−1. These CF2 energies, coupled with the available thermochemical data, allow us to determine unambiguously that CF2 production must be accompanied by the production of two atomic Br fragments. A photofragment excitation spectrum of CF2Br2, probing for the production of CF2 fragments, provided a reaction threshold of 460±3 kJ mol−1 (corresponding to 260±1.5 nm). The range of previously published reaction enthalpies varies from 392 to 438 kJ mol−1, all of which are substantially below the observed threshold. Additionally, at Ediss=486 kJ mol−1, the energy of the CF2 fragment was 27 kJ mol−1 on average, already in excess of the available 26 kJ mol−1, and without considering the kinetic energy of the recoiling Br atoms. We rationalise these data by proposing that the reaction might have a small barrier in the exit channel. The observed threshold corresponds to the top of the barrier (460 kJ mol−1), while the final energy in the fragments is determined by the asymptotic reaction energy (∽424 kJ mol−1). Simple dynamical models are presented to show that the proposed mechanism is reasonable. Key future experiments and calculations are identified that would enable a clearer picture of the dynamics of this reaction.

  这 CF2Br2+hν–CF2+2 Br 反应的解离动力学已针对各种解离能进行了研究，Ediss=460–535 kJ mol–1 （相当于 δ=260-223 nm）。激光诱导荧光光谱 新生 CF2 测量了产品在此范围内的各种离解能。分析 光谱分析得出 CF2 振动分布和平均旋转能。 CF2 的平移能量是通过各种完全分辨的 rovibronic 的多普勒展宽来测量的 过渡。对 CF2 碎片中的能量处置进行了最详细的分析 Ediss=486 kJ mol−1（或δ=246 nm）。在此能量下，CF2每个自由度的平均能量为Evib=0.4±0.2 kJ mol-1，Erot=2.5±0.5 kJ mol-1，Etrans=24±3 kJ mol-1。这些 CF2 能量，加上 现有的热化学数据使我们能够明确地确定 CF2 的产生必定伴随着两个原子 Br 碎片的产生。 CF2Br2 的光碎片激发光谱，探测 CF2 碎片的产生，提供了 460±3 kJ mol–1 的反应阈值 （相应的 至 260±1.5 nm）。先前发表的反应焓范围从 392 到 438 kJ mol·1 不等，全部 远低于观察到的阈值。此外，在 Ediss=486 kJ mol−1 时，CF2 的能量 碎片平均为 27 kJ mol-1，已经超过了可用的 26 kJ mol-1，并且不考虑反冲 Br 原子的动能。我们通过提出反应在出口通道中可能有一个小障碍来合理化这些数据。观察到的阈值对应于势垒的顶部 (460 kJ mol-1)，而碎片中的最终能量由渐近反应能 (-424 kJ mol-1) 决定。 简单的动力学模型表明所提出的机制是合理的。确定了未来的关键实验和计算，可以更清楚地了解该反应的动态。
• Skorobogatov; Dymov; Nedozrelova, Russian Journal of General Chemistry, 1996, vol. 66, # 11, p. 1777 - 1785
  作者：Skorobogatov、Dymov、Nedozrelova

  DOI：——

  日期：——
• 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.