主链含有寡乙烯通过环开放聚合 9-H-9-甲
Alexander Hübner1, Zheng-Wang Qu, Ulli Englert
1Institut für Anorganische und Analytische Chemie, Johann Wolfgang Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany.
Journal of the American Chemical Society
|March 4, 2011
概括
9-H-9-甲 (5) 通过in situ生成形成独特的二元和寡聚物. 这些具有B-H-B键和桥环的结构以NMR和X射线晶体学为特征.
科学领域:
- 有机金属化学 有机金属化学
- 化学 化学 化学
- 聚合物化学 聚合物化学
背景情况:
- 9-H-9-博拉 (5) 在现场从9-Br-9-博拉和Et(3) SiH中合成.
- 在标准反应条件下,在现场生成的5个形式是C(1) - 对称的二次体 (5).
研究的目的:
- 为了阐明由9-H-9-borafluorene形成的二元体 (5) (((2) 的结构.
- 为了研究二聚体 (5) (2) 在 adduct 形成和水反应中的反应性.
- 探索9-H-9-波拉烯的长期稳定性和寡合化途径.
主要方法:
- 在现场生成9-H-9-borafluorene.
- 用于反应监测和结构分析的NMR光谱 (1H, 13C, 11B).
- 密度函数理论 (DFT) 计算用于异构体分析和机理阐明.
- 用X射线结晶学来确定关键化合物的结构特征.
- 反应产品的分离和表征,包括二聚物,和寡聚物.
主要成果:
- 二元体 (5) (((2) 具有独特的结构,具有B-H-B三中心,两电子键和桥环,而不是经典的二元体.
- (5) (((2) 清洁地与皮里丁反应,形成添加物 (5·py) 并用三甲乙烯进行化,产生产物9及其衍生物.
- 在溶液中长期不稳定的 (5) (((2) 会导致环开放的二聚体 (例如,10·py (((2)) 和五聚体 (11),以及相关的寡聚体 (12,13).
- 在反流二烯条件下形成一个循环二元体 (14).
- 化合物9,10·py(2),11,12,13,和14通过X射线结晶学进行了结构确认.
结论:
- 这项研究揭示了9-H-9-博拉的复杂结构和反应行为,包括其二分化和倾向于环开放聚合的倾向.
- DFT计算提供了对反应路径和结构赋值的全面了解.
- 这些发现提供了对9 - 玻拉烯环开放聚合的机制情景的见解.
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