N-Methyl-N-9-triptycylacetamide exists as the Z-isomer in the crystalline state and the amide nitrogen is considerably pyramidal, while in solution the compound exists as a mixture of E/Z isomers, the equilibrium being dependent on the solvent and the temperature.
N-Methyl-N-9-triptycylacetamide 在结晶状态下为 Z 异构体,酰胺氮呈明显的金字塔形,而在溶液中,该化合物为 E/Z 异构体的混合物,其平衡取决于溶剂和温度。
Structures and Stereodynamics of<i>N</i>-9-Triptycylacetamide and Its<i>N</i>-Alkyl Derivatives
pyramidalized. In solution, 1 exists solely as the Z-isomer, while 2, 3, and 4 exist as an equilibrium mixture of the Z- and E-isomers. The isomer ratio is not correlated with the bulkiness of the N-alkyl group; the N-ethyl compound 3 seems to behave anomalously. The isomer ratio is significantly dependent on the solvent; the population of the Z-isomer in 2 or 3 or 4 increases with the solvent polarity. The Z E
对 N-9-三苯乙酰胺 (1)、N-甲基-N-9-三苯乙酰胺 (2)、N-乙基-N-9-三苯乙酰胺 (3) 和 N-苄基-N-9-三苯乙烯基乙酰胺 (4)。在结晶状态下,化合物 1、2 和 4 仅作为酰胺键的 Z 异构体存在,而等量的 Z 和 E 异构体存在于化合物 3 的单晶中。 2 中的酰胺氮原子、 3 或 4 显着金字塔化。在溶液中,1 仅作为 Z 异构体存在,而 2、3 和 4 作为 Z 和 E 异构体的平衡混合物存在。异构体比例与 N-烷基的体积无关;N-乙基化合物3似乎表现异常。异构体比例显着取决于溶剂;Z-异构体在 2 或 3 或 4 中的数量随着溶剂极性的增加而增加。ZE 互变发生在环境温度附近的 NMR 时间尺度上,屏障取决于溶剂;羟基溶剂,遇...