• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>International Symposium on Fullerenes 2000 Vol.8: Electrochemistry and Photochemistry, May 14-18, 2000, Toronto >Effects of Lowering Symmetry on the ESR Spectra of Radical Anions of Fullerene Derivatives
【24h】

Effects of Lowering Symmetry on the ESR Spectra of Radical Anions of Fullerene Derivatives

机译：降低对称性对富勒烯衍生物自由基阴离子的ESR谱的影响

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

Radical anions of dibenzyl adducts of C_(60), 1,4-(C_6H_3CH_2)_2C_(6o)~(dot -) and l,2-(C_6H_5CH_2)_2C_(60)~(dot -), give ESR spectra which have larger g values (2.0004 and 2.0001, respectively) and much smaller linewidths (ΔH_(msl) = 2.5 and 3.9 G, respectively at 213 K) than the g value (1.9984) and the ΔH_(msl) value (30.9 G at 213 K) of C_(60)~(dot -). An even smaller ΔH_(msl) value (0.17 G) and a larger g value (2.0011) are observed in the tetrabenzyl C_(60) adduct radical anion, l,4,10,24-(C_6H_5CH_2)_4C_(60)~(dot -). This is ascribed to a large splitting of the degenerate t_(lu) orbitals caused by introduction of four benzyl groups to C_(60). In this case, a hyperfine structure, due to two nonequivalent protons of only one benzyl group (aH_1 = 0.31 G, aH_2 = 0.11 G), is observed and this is consistent with the predicted localized spin density at the C2 position next to the Cl carbon to which a benzyl group is attached. The radical anions of the mono- and bisadducts formed in the Diels-Alder cycloaddition reaction of C_(60) with 9,10-dimethylanthracene show ESR signals at different g values (2.0003 for the monoadduct and 2.0009 for the bisadduct). The relationship between lower symmetry and the ESR spectra of radical anions of various C_(60) derivatives is discussed based on the change in the g values and the linewidths. The energy gap ( δ) between the singly occupied orbital and the two other orbitals which had the t_(lu) symmetry prior to introduction of addends to C_(60) is derived from the difference in the g values of various C_(60)~( dot -) derivatives from the free spin value (2.0023). There is a linear correlation between log ΔH_(msl) and - δ.
机译：C_（60），1,4-（C_6H_3CH_2）_2C_（6o）〜（点-）和l，2-（C_6H_5CH_2）_2C_（60）〜（点-）的二苄基加成物的自由基阴离子给出具有与g值（1.9984）和ΔH_（msl）值（213 K时为30.9 G）相比，较大的g值（分别为2.0004和2.0001）和更小的线宽（ΔH_（msl）分别为2.5和3.9 G在213 K下） ）的C_（60）〜（点-）。在四苄基C_（60）加合物自由基阴离子l，4,10,24-（C_6H_5CH_2）_4C_（60）〜（）中观察到甚至更小的ΔH_（msl）值（0.17 G）和更大的g值（2.0011）。点-）。这归因于由于将四个苄基引入C_（60）而引起的简并的t_（lu）轨道的大分裂。在这种情况下，由于仅一个苄基的两个非等价质子（aH_1 = 0.31 G，aH_2 = 0.11 G），观察到超精细结构，这与在Cl附近的C2位置的预测局部自旋密度相符苄基所连接的碳。在C_（60）与9,10-二甲基蒽的Diels-Alder环加成反应中形成的单加合物和双加合物的自由基阴离子显示出不同g值的ESR信号（单加合物为2.0003，双加合物为2.0009）。基于g值和线宽的变化，讨论了各种C_（60）衍生物的自由基阴离子的下对称性与ESR谱的关系。从各个C_（60）〜的g值之差推导在单个被占据的轨道与在将加数引入C_（60）之前具有t_（lu）对称性的两个其他轨道之间的能隙（δ） （点-）来自自由旋转值（2.0023）的导数。 logΔH_（msl）与-δ之间存在线性关系。

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