• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>other >Generating Cu(II)-Oxyl / Cu(III)-Oxo Species from Cu(I)-α-Ketocarboxylate Complexes and O2: In silico Studies on Ligand Effects and C-H-activation Reactivity
【2h】

Generating Cu(II)-Oxyl / Cu(III)-Oxo Species from Cu(I)-α-Ketocarboxylate Complexes and O2: In silico Studies on Ligand Effects and C-H-activation Reactivity

机译：从Cu（I）-α-酮羧酸酯配合物和O2生成Cu（II）-Oxyl / Cu（III）-Oxo物种：配体效应和C-H活化反应性的计算机模拟研究

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A mechanism for the oxygenation of Cu(I) complexes with α-ketocarboxylate ligands is elaborated that is based on a combination of density functional theory and multireference second-order perturbation theory (CASSCF/CASPT2) calculations. The reaction proceeds in a manner largely analogous to those of similar Fe(II) α-ketocarboxylate systems, i.e. by initial attack of a coordinated oxygen molecule on a ketocarboxylate ligand with concomitant decarboxylation. Subsequently, two reactive intermediates may be generated, a Cu-peracid structure and a [CuO]+ species, both of which are capable of oxidizing a phenyl ring that is a component of the supporting ligand. Hydroxylation by the [CuO]+ species is predicted to proceed with a smaller activation free energy. The effects of electronic and steric variatons on the oxygenation mechanisms were studied by introducing substituents at several positions of the ligand backbone and by investigating various N-donor ligands. In general, more electron-donation by the N-donor ligand leads to increased stabilization of the more Cu(II)/Cu(III)-like intermediates (oxygen adducts and [CuO]+ species) relative to the more Cu(I)-like peracid intermediate. For all ligands investi-gated, the [CuO]+ intermediates are best described as Cu(II)-O•- species having triplet ground states. The reactivity of these compounds in C-H abstraction reactions decreases with more electron-donating N-donor ligands, which also increase the Cu-O bond strength, although the Cu-O bond is generally predicted to be rather weak (with a bond order of about 0.5). A comparison of several methods to obtain singlet energies for the reaction intermediates indicates that multireference second-order perturbation theory is likely more accurate for the initial oxygen adducts, but not necessarily for subsequent reaction intermediates.
机译：阐述了基于密度泛函理论和多参考二级扰动理论（CASSCF / CASPT2）计算的Cu（I）配合物与α-酮羧酸酯配体的氧合机理。该反应以与相似的类似Fe（II）α-酮羧酸酯体系相似的方式进行，即通过配位的氧分子对酮羧酸酯配体的初始攻击并伴随着脱羧作用。随后，可以产生两个反应性中间体，即Cu-过酸结构和[CuO] sup + sup物种，它们都能够氧化作为支撑配体的组分的苯环。预计[CuO] + 物种的羟化反应会以较小的活化自由能进行。通过在配体主链的几个位置引入取代基并研究各种N供体配体，研究了电子和空间变异对氧合机理的影响。通常，N-供体配体的更多电子给体会导致更多类似Cu（II）/ Cu（III）的中间体（氧加合物和[CuO] + 物种）的稳定性提高。到更像Cu（I）的过酸中间体。对于所有研究的配体，[CuO] + 中间体最好描述为具有三重态基态的Cu（II）-O •-物种。这些化合物在CH提取反应中的反应性随更多的电子给体N-给体配体而降低，这也增加了Cu-O键的强度，尽管通常预测Cu-O键的强度很弱（键序约为0.5）。几种获得反应中间体单重态能量的方法的比较表明，多参考二级扰动理论对于初始氧加合物可能更准确，但对于随后的反应中间体则不一定。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号