Benzodisilacyclobutadienes: 8π-Electron Systems with an Antiaromatic Silicon Ring
Benzodisilacyclobutadienes: 8π-Electron Systems with an Antiaromatic Silicon Ring
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苯并二硅环丁二烯：具有反芳香族硅环的 8π 电子系统
DOI：
10.1002/anie.201707553
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Iwamoto Takeaki
中科院分区：
文献类型：
--
作者：
Ishida Shintaro;Misawa Yoshifumi;Sugawara Shohei;Iwamoto Takeaki
在钾石墨存在下，稳定的二硅炔1和1，2-二溴苯反应，分离出苯并二硅环丁二烯2 a-c，为蓝色至绿色结晶固体。在固态下，观察到2a-c的苯环内有大量的键交替。在正己烷中，2a-c在625-670 nm处的π→π*（HOMO→LUMO）吸收带发生明显的红移。 NMR谱和理论计算表明，反芳环1，2-二硅杂环丁二烯的贡献大大降低了2 a-care苯环的抗磁性环电流.整体而言，所获得的结果表明，2a-产生含有反芳族1，2-二硅杂环丁二烯的8π电子系统。
Benzodisilacyclobutadienes2 a–cwere isolated as blue to green crystalline solids from the reaction of stable disilyne1and 1,2‐dibromobenzenes in the presence of potassium graphite. In the solid state, substantial bond alternation was observed within the benzene rings of2 a–c. In hexane,2 a–cshowed remarkable bathochromic shifts of the π→π* (HOMO→LUMO) absorption bands at 625–670 nm. NMR spectra and theoretical calculations indicated that the diamagnetic ring currents of the benzene rings of2 a–care considerably reduced by contributions from the antiaromatic 1,2‐disilacyclobutadienes. In their entirety, the obtained results indicate that2 a–crepresent 8π‐electron systems that contain an antiaromatic 1,2‐disilacyclobutadiene.