...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >A theoretical study of the reactivity of ethene and benzophenone with a hyper-coordinated alkene containing a so-called E=E (E = C, Si, Ge, Sn, and Pb) unit
【24h】

A theoretical study of the reactivity of ethene and benzophenone with a hyper-coordinated alkene containing a so-called E=E (E = C, Si, Ge, Sn, and Pb) unit

机译：乙烯和二苯甲酮与含有所谓的E = e（E = C，Si，Ge，Sn和Pb）单元的超协调烯烃反应性的理论研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The reactivity of a reported hyper-coordinated alkene (Rea-E; Rea = reactant; E = group 14 element) featuring a central E=E moiety was theoretically analyzed using DFT (density functional theory) and the EDA-NOCV (energy decomposition analysis-natural orbitals for chemical valence) method. M06-2X/def2-SVP and B3LYP-D3/def2-SVP results demonstrate that five Rea-E molecules have an energy minimum as their structures have no imaginary frequency. Theoretical examinations based on three types of bond order calculations (Wiberg, Mayer, and Fuzzy), the LOL (localized orbital locator) analyses, Lewis structures and the NBO (natural bond orbital) analyses suggest that a very weak central Si-Si single bond and an extremely weak central Ge-Ge single bond, rather than a double bond, are present in the Rea-Si and Rea-Ge molecules, respectively. On the other hand, no bond is found between the two central group 14 atoms in Rea-C, Rea-Sn, and Rea-Pb. The theoretical investigation demonstrates that the reactivity of the Rea-E compound decreases in the order Rea-Si > Rea-Ge > Rea-C, a trend that results from the differences in the atomic radii of the group 14 elements. Carbon has the smallest atomic radius in the group 14 family, causing steric crowding between Rea-C and other attacking species. This circumstance, in turn, increases the activation energies of its addition reactions and renders these reactions energetically infeasible. For the cyclic product of Rea-Ge, the theoretical evidence reveals that the comparatively large atomic radius of Ge induces the weakest Pauli repulsions and the smallest overlap integrals between Rea-Ge and the other doubly bonded molecules. This situation, in turn, makes the overall cyclization reaction of Rea-Ge endothermic. As a result, only the silicon-centered molecule, Rea-Si, can undergo the [2 + 2] cycloaddition reactions with doubly bonded molecules without kinetic or thermodynamic difficulty, which agrees well with the available experimental findings.
机译：通过DFT（密度函数理论）和EDA-NOCV（能量分解分析，理论上分析了报告的超协调烯烃（Rea-E; Rea =反应物; E =组14元件）的反应性。用于化学价的自然轨道）方法。 M06-2X / DEF2-SVP和B3LYP-D3 / DEF2-SVP结果表明，由于其结构没有虚频，5个REA-E分子具有最小能量。基于三种类型的债券订单计算（Wiberg，Mayer和Fuzzy），LOL（局部化轨道定位器）分析，Lewis结构和NBO（天然键轨道）分析的理论检查表明，中央Si-Si单键非常弱在Rea-Si和Rea-Ge分子中存在极其弱的中央Ge-Ge单键，而不是双键。另一方面，在Rea-C，Rea-Sn和Rea-Pb中的两个中央组14原子之间没有发现粘合。理论上的研究表明，Rea-E化合物的反应性在Rea-Si> Rea-Ge> Rea-C中减少，这是由第14项元素的原子半径的差异产生的趋势。碳在14组家庭中具有最小的原子半径，导致Rea-C和其他攻击物种之间的空间拥挤。这种情况又增加了其添加反应的激活能量，并使这些反应能够充满活力。对于Rea-GE的循环产物，理论上的证据表明，GE的相对大的原子半径诱导了最弱的Pauli排斥和Rea-Ge与其他双键分子之间的最小重叠积分。反过来，这种情况又使Rea-Ge吸热的整体环化反应。结果，只有硅居中分子，Rea-Si，可以通过无动力学或热动力学难度的双键合分子进行[2 + 2]环加成反应，这与可用的实验结果很好。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

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