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第18讲-线性和循环共轭理论；4n+2芳香性Lecture 18 - Linear and Cyclic Conjugation Theory; 4n+2 Aromaticity |
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| 课程网址: | http://videolectures.net/yalespan125bs2011_mcbride_lec18/ |
| 主讲教师: | J. Michael McBride |
| 开课单位: | 耶鲁大学 |
| 开课时间: | 2014-08-19 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Despite the substantial change in the energy of individual orbitals, the overall pi-electron energy and orbital shape changes little upon linear conjugation of two double bonds. Conjugation energy of polyenes and allylic systems may be predicted by means of a semicircle mnemonic. The much greater stabilization in "aromatic" conjugated rings, and Hückel's 4n+2 rule, derive from alternating stabilization and destabilization of successive orbitals when the ends of a conjugated chain overlap as it is closed to form a ring. A circle mnemonic predicts orbital energies for conjugated rings. This aromaticity concept is generalized to heteroaromatic compounds like furan and imidazole, to polycyclic compounds like naphthalene, and to hydrocarbon ions like cyclopentadienide. |
| 关 键 词: | 双键线性共轭; 半圆记忆法预测; 共轭链 |
| 课程来源: | 视频讲座网 |
| 数据采集: | 2021-11-12：zkj |
| 最后编审: | 2021-11-12：zkj |
| 阅读次数: | 40 |