Laird Mathilde, Herrmann Niklas, Ramsahye Naseem, Totée Cédric, Carcel Carole, Unno Masafumi, Bartlett John R, Wong Chi Man Michel
ICGM, Univ. Montpellier, CNRS, ENSCM, Montpellier, France.
Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, Kiryu, 376-8515, Gunma, Japan.
Angew Chem Int Ed Engl. 2021 Feb 8;60(6):3022-3027. doi: 10.1002/anie.202010458. Epub 2020 Dec 3.
The synthesis of organo-functionalized polyhedral oligomeric silsesquioxanes (POSS, (R-SiO ) , T ) is an area of significant activity. To date, T is the largest such cage synthesized and isolated as a single isomer. Herein, we report an unprecedented, single-isomer styryl-functionalized T POSS. Unambiguously identified among nine possible isomers by multinuclear solution NMR ( H, C, and Si), MALDI-MS, FTIR, and computational studies, this is the largest single-isomer functionalized T compound isolated to date. A ring-strain model was developed to correlate the Si resonances with the number of 6-, 5-, and/or 4-Si-atom rings that each non-equivalent Si atom is part of. The model successfully predicts the speciation of non-equivalent Si atoms in other families of T compounds, demonstrating its general applicability for assigning Si resonances to Si atoms in cage silsesquioxanes and providing a useful tool for predicting Si-atom environments.
有机官能化多面体低聚倍半硅氧烷（POSS，(R-SiO ) ，T ）的合成是一个具有重要研究活性的领域。迄今为止，T 是合成并分离得到的最大的此类单一异构体笼状化合物。在此，我们报道了一种前所未有的单异构体苯乙烯基官能化 T POSS。通过多核溶液核磁共振（ H、 C 和 Si）、基质辅助激光解吸电离质谱（MALDI-MS）、傅里叶变换红外光谱（FTIR）以及计算研究，在九种可能的异构体中明确鉴定出了该化合物，这是迄今为止分离得到的最大的单异构体官能化 T 化合物。我们建立了一个环应变模型，将 Si 共振与每个不等价 Si 原子所属的 6、5 和/或 4 个 Si 原子环的数量相关联。该模型成功预测了其他 T 化合物家族中不等价 Si 原子的形态，证明了其在笼状倍半硅氧烷中将 Si 共振分配给 Si 原子的普遍适用性，并为预测 Si 原子环境提供了一个有用的工具。
