p-methylphenoxyl radical | 3174-48-9

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: p-methylphenoxyl radical
• 英文别名: 4-Me-phenoxy
• CAS: 3174-48-9
• 化学式: C₇H₇O
• 分子量: 107.132
• InChiKey: LTKOYWPELWFYHK-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  8
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.14
• 拓扑面积：
  1
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  p-methylphenoxyl radical 在 Sodium borate 、 sodium azide 、 一氧化二氮 、 叔丁醇 作用下， 以 水 为溶剂， 生成 sodium 4-methylphenoxide
  参考文献：
  名称：

  涉及苯氧基的自由基组合反应

  摘要：

  The rates of phenoxyl radical reactions with the superoxide anion radical, O2.-, a peroxyl radical, HOC(CH3)2CH2OO., and an alkyl radical, HOC(CH3)2CH2., in aqueous solution have been measured for 15 different phenoxyl radicals by means of pulse radiolysis. In addition, the one-electron reduction potentials of 10 phenoxyl radicals have been determined. The fraction of electron transfer in the reaction of phenoxyl radicals with O2.-was determined by analysis of gamma-irradiated samples. The experimental data can be accommodated by the Marcus theory for electron transfer, with the reorganization energy lambda-degrees = 155 kJ/mol for the reaction between O2.- and phenoxyl radicals.

  DOI：

  10.1021/j100133a018
• 作为产物：
  描述：

  4-甲基苯酚阴离子 在 二氧化氮 作用下， 以 水 为溶剂， 生成 p-methylphenoxyl radical
  参考文献：
  名称：

  取代基对二氧化氯，二氧化氮和三氧合硫酸根（1-）自由基对酚的单电子氧化速率的影响

  摘要：

  DOI：

  10.1021/j100408a063

文献信息

• Oxidation of phenols employing polyoxometalates as biomimetic models of the activity of phenoloxidase enzymes
  作者：Carlo Galli、Patrizia Gentili、Ana Sofia Nunes Pontes、Jose A. F. Gamelas、Dmitry V. Evtuguin

  DOI：10.1039/b703178e

  日期：——

  the experimental oxidation data. A sizeable value for the reorganisation energy (λ) was accordingly obtained. The slightly stronger oxidant SiW11Mn resulted to be more reactive than SiW11V by ca. two powers of magnitude. Our scrutiny of the reactive behaviour of the two POMs towards phenols may provide a model of interpretation for the phenoloxidase activity of the laccase enzymes, a class of multicopper

  取代基氧化的动力学研究 酚类与任一钒（V）polyoxotungstate，[α-SIV V w ^ 11 ö 40 ] 5-（即硅钨酸11 V），或锰（III）polyoxotungstate，[α-硅锰III W¯¯ 11（H 2 O）O- 39 ] 5-（即硅钨酸11的Mn），已经进行了。因为多金属氧酸盐SiW 11 V和SiW 11 Mn化合物的氧化还原电位，即。POM为0.67和0.76 V /NHE以及酚醛底物的电压分别在0.4-0.9 V /NHE 在 水，所产生的氧化反应是外能的或轻微的内能的。的反应性氧化作用 的替代 酚类通过SiW 11 V，在50°C的缓冲水溶液（pH = 4）中，发现与取代基的σ +参数相关，产生与电子共振的冈本-布朗ρ值（即-3.1）决定速率的电子转移途径的要求。的微不足道的价值溶剂用SiW 11 V氧化p -MeO-苯酚获得动力学同位素效应（k H
• Reaction of tert-butoxy radicals with phenols. Comparison with the reactions of carbonyl triplets
  作者：P. K. Das、M. V. Encinas、S. Steenken、J. C. Scaiano

  DOI：10.1021/ja00404a030

  日期：1981.7

  Tert-butoxy radicals generated in the photodecomposition of di-tert-butyl peroxide react efficiently with phenols to yield the corresponding phenoxy radicals. Typical rate constants in benzene at 22/sup 0/C are 3.3 x 10/sup 8/ and 1.6 x 10/sup 9/ M/sup -1/ s/sup -1/ for phenol and p-methoxyphenol, respectively. The process is considerably slower in polar solvents; e.g., when pyridine is used as cosolvent

  二叔丁基过氧化物光分解中产生的叔丁氧基自由基与酚类有效反应生成相应的苯氧基自由基。苯中的典型速率常数在 22/sup 0/C 时分别为 3.3 x 10/sup 8/ 和 1.6 x 10/sup 9/ M/sup -1/ s/sup -1/ 苯酚和对甲氧基苯酚。该过程在极性溶剂中要慢得多；例如，当使用吡啶作为助溶剂时，苯酚的速率常数下降到 4.1 x 10/sup 6/ M/sup -1/ s/sup -1/，这是由于强氢键降低了酚类 OH 的反应性团体。同位素效应 (H/D) 通常在 3 到 5 的范围内。5个数字，4个表格。
• Bimolecular Hydrogen Abstraction from Phenols by Aromatic Ketone Triplets†
  作者：Edward C. Lathioor、William J. Leigh

  DOI：10.1562/2005-06-20-ra-581

  日期：——

  with reaction via two mechanisms: a simple electron-transfer mechanism, which applies to the n,π* triplet ketones and those π,π* triplets that possess particularly low reduction potentials, and a coupled electron-/proton-transfer mechanism involving the intermediacy of a hydrogen-bonded exciplex, which applies to the π,π* ketone triplets. Ketones with lowest charge-transfer π,π* states exhibit rate

  摘要 在 23°C 的乙腈溶液中测定了 24 种芳香酮的最低三线态从 4-甲基苯酚（对甲酚）中夺氢的绝对速率常数，并将结果与​​之前报道的大约十几种其他化合物的数据相结合在相同条件下。研究的酮包括各种环取代的二苯甲酮和苯乙酮、α,α,α-三氟苯乙酮及其 4-甲氧基类似物、2-苯甲酰噻吩、2-乙酰萘以及各种其他多环芳香酮，如芴酮、呫吨酮和噻吨酮，包括n,π*, π,π*(CT) 和皂素 π,π* 最低三重态，具有（三重态）还原电位 (Ered*) 从大约 -10 到 -38 kcal mol-1 变化。几乎在所有情况下，4-甲基苯氧基自由基都被观察为三重态猝灭的产物，在大多数情况下与相应的hemipinacol自由基一起。苯乙酮和二苯甲酮的哈米特图完全不同，但 log kQ 与 Ered* 的图显示了大多数研究化合物的共同行为。结果与通过两种机制的反应一致：简单的电子转移机制，适用于 n,π*
• Laser flash photolysis determination of absolute rate constants for reactions of bromine atoms in solution
  作者：J. C. Scaiano、M. Barra、M. Krzywinski、R. Sinta、G. Calabrese

  DOI：10.1021/ja00071a048

  日期：1993.9

  dibromides at 266 nm produces bromine atoms with a quantum yield of ∼2.0. This results from an efficient primary photocleavage of a C-Br bond, followed by rapid elimination of a second bromine atom from radicalsofthe type RCH-CH 2 Br. This cleavage occurs with a lifetime of <20 ns at room temperature. Bromine atoms react with bromine ions with a rate constant of 1.6×10 10 M -1 s -1 to yield Br 2 .-

  邻位二溴化物在 266 nm 处的光分解产生量子产率为~2.0 的溴原子。这是由于 C-Br 键的有效初级光裂解，然后从 RCH-CH 2 Br 型自由基中快速消除了第二个溴原子。这种裂解在室温下以 <20 ns 的寿命发生。溴原子与溴离子以1.6×10 10 M -1 s -1 的速率常数反应生成Br 2 .- ，一种易于检测且寿命长的自由基离子。该反应可用作探针以确定溴原子其他反应的绝对速率常数
• Factors Influencing the Antioxidant Activities of Phenols by an Ab Initio Study.
  作者：Shogo Tomiyama、Shogo Sakai、Tomihiro Nishiyama、Fukiko Yamada

  DOI：10.1246/bcsj.66.299

  日期：——

  An ab initio molecular orbital theory has been applied to the elucidation of the hydrogen abstraction mechanism of phenolic antioxidants in the chain process of autoxidations. The optimum structures of o-, m-, and p-substituted phenols, of peroxides, and of those compounds in the transition states were obtained with a Hartree-Fock/STO-3G basis set. From the values of the enthalpy (ΔH), activation (Ea), and OH bond dissociation (D(O–H)) energies obtained, it was found that these three parameters indicate a good relationship with each other; particularly, the relation between the ΔH and Ea values follows the Evans-Polanyi rule. The electron-releasing substituents in the o- and p-positions in phenols decrease the activation parameters for hydrogen abstraction, while those in the m-position increase. The electron densities on the ipso-carbon, oxygen, and hydrogen of the OH substituent and their bond populations are obtained. Variations of the electron densities from the reactants to the transition states lead to a clarification of the reaction mechanism as an antioxidant. Namely, the gain or loss of electrons in the reaction states may be correlated to the experimental data, 13C chemical shifts of the ipso-carbon of the OH substituent, and the values of the induction period as an antioxidant activity.

  从头算分子轨道理论已被应用于阐明酚类抗氧化剂在自氧化链式反应中的夺氢机理。通过使用哈特里-福克/STO-3G基组，得到了邻、间、对位取代酚、过氧化物以及过渡态化合物的优化结构。从获得的焓变（ΔH）、活化能（Ea）和羟基键解离能（D(O–H)）值来看，这三个参数之间显示出良好的相关性；特别是ΔH和Ea值之间的关系遵循埃文斯-波拉尼规则。酚类化合物中邻位和对位上的供电子取代基会降低夺氢反应的活化参数，而间位上的取代基则会提高这些参数。计算得到了OH取代基的ipso碳、氧、氢上的电子密度及其键的布居数。从反应物到过渡态电子密度的变化有助于阐明抗氧化剂反应机理。即，反应态中电子的增益或损失可能与实验数据、OH取代基的ipso碳的13C化学位移以及抗氧化活性的诱导期值相关联。