p-methoxycumyl radical | 98325-44-1

• 分子结构分类: 有机化合物 - 苯类化合物
• 英文名称: p-methoxycumyl radical
• CAS: 98325-44-1
• 化学式: C₁₀H₁₃O
• 分子量: 149.213
• InChiKey: LBFXTCKDKXVVQK-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  11
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.3
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为产物：
  描述：

  1-异丙烯基-4-甲氧基苯 在 6H-苯并[cd]芘 9,10-二氢蒽 作用下， 以 二苯醚 为溶剂， 生成 p-methoxycumyl radical
  参考文献：
  名称：

  摘要：

  DOI：

  10.1002/(sici)1099-0690(199909)1999:9<2219::aid-ejoc2219>3.3.co;2-4

文献信息

• Lifetimes and UV-visible absorption spectra of benzyl, phenethyl, and cumyl carbocations and corresponding vinyl cations. A laser flash photolysis study
  作者：Frances L Cozens、V M Kanagasabapathy、Robert A McClelland、Steen Steenken

  DOI：10.1139/v99-210

  日期：1999.12.5

  Benzyl (4-MeO, 4-Me, and 4-methoxy-1-naphthylmethyl), phenethyl (4-Me₂N, 4-MeO, 3,4-(MeO)₂, 4-Me, 3-Me, 4-F, 3-MeO, 2,6-Me₂, parent, and 4-methoxy-1-naphthylethyl) and cumyl (4-Me₂N, 4-MeO, 4-Me, parent) cations have been studied by laser flash photolysis (LFP) in 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). In most cases styrene or α-methylstyrene precursors were employed for the phenethyl and cumyl ions, the intermediate being obtained by solvent protonation of the excited state. Benzyl cations were generated by photoheterolysis of trimethylammonium and chloride precursors. While a 4-MeO substituent provides sufficient stabilization to permit observation of cations in TFE, cations with less stabilizing substituents usually require the less nucleophilic HFIP. Even in this solvent, the parent benzyl cation is too short-lived (lifetime <20 ns) to be observed. When generated in HFIP, phenethyl cations can be seen to react with unphotolyzed styrene, giving rise to dimer cations that are observed to grow in as the initial phenethyl cation decays. The dimer cations, in common with the oligomer cations seen in cationic styrene polymerization, have a λ_max 15-20 nm higher than the monomer and react with both solvent and styrene several orders of magnitude more slowly. This stabilization relative to the phenethyl may reflect an interaction with the aryl group present at the gamma-carbon. Cations 4-MeOC₆H₄C⁺(R)-CH₃ (R = Me, Et, i-Pr, t-Bu, cyclopropyl, C₆H₅, 4-MeOC₆H₄) were generated in TFE via the photoprotonation route. The alkyl series shows that steric effects are important in the decay reaction. The cation with R = cyclopropyl is a factor of 1.5 less reactive than the cation where R = phenyl. Several vinyl cations have also been generated by photoprotonation of phenylacetylenes. ArC⁺=CH₂ has a reactivity very similar to that of its analog ArC⁺H-CH₃, the vinyl cation being slightly (factors of 2-5) shorter-lived. For the various series of cations, including vinyl, substituents in the aryl ring have a consistent effect on the λ_max, a shift to higher wavelength relative to hydrogen of 15 nm for 4-Me, 30 nm for 4-MeO, and 50 nm for 4-Me₂N.Key words: photogenerated carbocations, carbocation lifetime, styrene, photoprotonation.

  苯甲基（4-MeO，4-Me和4-甲氧基-1-萘基甲基）、苯乙基（4-Me2N，4-MeO，3,4-(MeO)2，4-Me，3-Me，4-F，3-MeO，2,6-Me2，母体和4-甲氧基-1-萘基乙基）和叔丁基（4-Me2N，4-MeO，4-Me，母体）阳离子在2,2,2-三氟乙醇（TFE）和1,1,1,3,3,3-六氟异丙醇（HFIP）中通过激光闪光光解（LFP）进行了研究。在大多数情况下，苯乙烯或α-甲基苯乙烯前体被用于苯乙基和叔丁基离子，中间体通过溶剂质子化激发态而获得。苯甲基阳离子是通过三甲基铵和氯化物前体的光异裂生成的。虽然4-MeO取代基提供了足够的稳定性以在TFE中观察到阳离子，但具有较少稳定取代基的阳离子通常需要较不亲核的HFIP。即使在这种溶剂中，母体苯甲基阳离子也太短寿命（寿命<20 ns）而无法观察到。在HFIP中生成的苯乙基阳离子可以看到与未经光解的苯乙烯反应，导致观察到的二聚体阳离子在初始苯乙基阳离子衰减时增长。与阳离子苯乙烯聚合中观察到的寡聚体阳离子一样，二聚体阳离子的λmax比单体高15-20 nm，并且与溶剂和苯乙烯反应速度慢几个数量级。相对于苯乙基的这种稳定性可能反映了与伽马碳上存在的芳基的相互作用。在TFE中通过光质子化途径生成了4-MeOC6H4C+(R)-CH3（R = Me，Et，i-Pr，t-Bu，环丙基，C6H5，4-MeOC6H4）阳离子。烷基系列表明立体效应在衰减反应中很重要。当R = 环丙基时，其反应性比R = 苯基的阳离子少1.5倍。还通过对苯乙炔的光质子化生成了几种乙烯阳离子。ArC+=CH2的反应性与其类似物ArC+H- 非常相似，乙烯阳离子寿命略短（2-5倍因子）。对于包括乙烯在内的各系列阳离子，芳香环中的取代基对λmax有一致的影响，相对于氢的15 nm的4-Me，30 nm的4-MeO和50 nm的4-Me2N的波长偏移。关键词：光产生的碳正离子，碳正离子寿命，苯乙烯，光质子化。
• Kinetic Study of the Hydrogen Abstraction Reaction of the Benzotriazole-<i>N</i>-oxyl Radical (BTNO) with H-Donor Substrates
  作者：Paolo Brandi、Carlo Galli、Patrizia Gentili

  DOI：10.1021/jo051615n

  日期：2005.11.1

  The aminoxyl radical (>N−O•) BTNO (benzotriazole-N-oxyl) has been generated by the oxidation of 1-hydroxybenzotriazole (HBT; >N−OH) with a CeIV salt in MeCN. BTNO presents a broad absorption band with λmax 474 nm and ε 1840 M-1 cm-1, and spontaneously decays with a first-order rate constant of 6.3 × 10-3 s-1 in MeCN at 25 °C. Characterization of BTNO radical by EPR, laser flash photolysis, and cyclic

  通过在MeCN中用Ce IV盐氧化1-羟基苯并三唑（HBT;> N-OH），生成了氨氧基（> NO •）BTNO（苯并三唑-N-氧基）。BTNO呈现一个宽吸收带与λ最大474纳米和ε1840中号- 1厘米- 1，并且自发地衰减具有6.3×10的一阶速率常数- 3小号- 1在25°C下的MeCN中。提供了通过EPR，激光闪光光解和循环伏安法对BTNO自由基进行表征的方法。在存在氢供体底物（如烷基芳烃，苄基和烯丙醇和链烷醇）的情况下，BTNO的自发衰减会大大加速，并且在25°C的光谱下已研究了BTNO从许多底物中吸氢的速率常数。动力学同位素效应证实了H提取步骤是决定速率的方法。激活参数已在15-40°C范围内使用选定的底物进行了测量。E a之间的相关性根据Evans-Polanyi方程获得了一系列小氢供体的BDE（CH）（CH键解离能），α= 0.44。从该图中可以推断出实验上不可用的苯甲醇的BDE（CH）。79
• Tertiary : secondary : primary C–H bond relative reactivity in the one-electron oxidation of alkylbenzenes. A tool to distinguish electron transfer from hydrogen atom transfer mechanisms
  作者：Enrico Baciocchi、Francesca D'Acunzo、Carlo Galli、Osvaldo Lanzalunga

  DOI：10.1039/p29960000133

  日期：——

  the HAT mechanism is operating the reactivity order tertiary > secondary > primary C–H bond is always observed. This order never holds in reactions occurring by an ET mechanism where, generally, the secondary C–H bond is the most reactive one and the tertiary centre can be either more or even less reactive than the primary one. Whatever the possible reasons for these differences, it turns out that TSP

  关于烷基苯的许多电子转移（ET）和氢原子转移（HAT）反应的叔，仲，伯C–H键相对反应性（TSP选择性）的数据已得到严格审查，在某些情况下还需要进行其他实验补充。所得图片表明，ET和HAT反应之间的TSP选择性存在显着差异。当HAT机制运行时，始终观察到反应顺序为三级>二级>一级C–H键。在由ET机制发生的反应中，这种顺序永远不会成立，在该反应中，通常，次级C–H键是反应性最高的键，而叔中心的反应性可能大于或小于初级键。不管造成这些差异的可能原因是什么，结果表明，TSP C–H键的选择性测定可提供有关烷基苯氧化中ET和HAT机理之间区别的有用信息。为了证实这一结论，已经进行了金属卟啉和微粒体细胞色素P-450促进的TSP在烷基苯氧化反应中的选择性研究，这使我们能够将HAT机理分配给这些反应，这与先前的归因完全一致。
• The Missing Link Between Molecular Triplets and Spin-Polarized Free Radicals: Room Temperature Triplet States of Nanocrystalline Radical Pairs
  作者：Natalia V. Lebedeva、Valery F. Tarasov、Marino J. E. Resendiz、Miguel A. Garcia-Garibay、Ryan C. White、Malcolm D. E. Forbes

  DOI：10.1021/ja909521u

  日期：2010.1.13

  states and short-lived intermediates in single crystals and powdered samples have been extremely challenging due to the high optical density and scattering power of single crystals and powdered samples. In this communication, we report the first direct observation of a radical pair triplet state by time-resolved electron paramagnetic resonance (TREPR) with nanocrystals of 4,4'-dimethoxy-dicumyl ketone (1OMe)

  固态有机分子的光化学反应在绿色化学技术中具有极好的潜力，因为它们通常以高产率进行，以提供单一产品而不会产生挥发性有机溶剂废物。虽然最近的合成应用强调需要更好地了解反应机制和动力学，但由于单晶和粉末样品的高光密度和散射能力，对单晶和粉末样品中激发态和短寿命中间体的光谱观察极具挑战性。粉末样品。在这篇通讯中，我们报告了通过时间分辨电子顺磁共振 (TREPR) 与悬浮在水中的 4,4'-二甲氧基-二枯基酮 (1OMe) 纳米晶体首次直接观察到自由基对三重态。1OMe 的稳态辐射先前表明，干粉和纳米晶悬浮液中的反应以高效率和化学选择性进行，通过脱羰和自由基偶联生成 4,4'-二甲氧基-二枯烯 2OMe。使用时间分辨 EPR 光谱仪腔内的流动系统，用 308 nm 的 25 ns 激光脉冲激发纳米晶悬浮液。所得的 TREPR 光谱显示出强烈的自旋极化，具有增强的吸收 A 和发射 E 信号，其特征为具有零场分裂参数
• Photobrominations of Substituted Cumenes by <i>N</i>-Bromosuccinimide:  Charge Delocalizations, Inductive Effects, and Spin Dispersions Triggered by Substituents
  作者：Sung Soo Kim、Chun Soo Kim

  DOI：10.1021/jo9905468

  日期：1999.12.1