The stereochemistry of calix[4]arenes capped by diamide bridges in the 1,3-position on the lower rim was established by 1H and 13C solution and solid state NMR. The 13C chemical shifts of Artext-decoration:underline'CH2Ar were found to be diagnostic of the cone, partial cone and 1,3-alternate conformations also in the solid state. Two sets of signals appearing in the CP/MAS spectra of 1,3-alternate and partial cone compounds indicate that these molecules occupy inequivalent sites in the elemental cell.
通过 1H 和 13C 溶液核磁共振以及固态核磁共振,确定了在下缘 1,3 位上以二酰胺桥封端的
钙[4]炔的立体
化学结构。研究发现,Artext-decoration:underline'CH2Ar 的 13C
化学位移也能在固态下诊断出锥体、部分锥体和 1,3- 别名构象。在 1,3 邻位和部分锥形化合物的 CP/MAS 光谱中出现的两组信号表明,这些分子在元素池中占据了不相等的位点。