Barriers to rotation of methyl groups in methyltriptycenes

F Imashiro, K Takegoshi, T Terao…

文献索引：Imashiro, Fumio; Takegoshi, Kiyonori; Terao, Takehiko; Saika, A. Journal of the American Chemical Society, 1982 , vol. 104, # 8 p. 2247 - 2251

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被引用次数: 10

摘要

Abstract: Rotational barriers of methyl groups in methyltriptycenes are determined from the temperature dependence of the'H spin-lattice relaxation times. Barriers of bridgehead methyls increase appreciably by methyl substitution at peri positions, which suggests probable absence of the gear effect. Calculations by the molecular mechanics (MMI) method and the molecular orbital (CNDO/FK) method favor a clashed-gear conformation for ...