Study of Cross-Conjugated <i>iso-</i>Polytriacetylenes and Related Oligoenynes
作者:Yuming Zhao、Robert McDonald、Rik R. Tykwinski
DOI:10.1021/jo015995y
日期:2002.5.1
Two series of monodisperse cross-conjugated oligomers based on enyne repeat units have been realized. The first class of molecules, iso-polytriacetylenes (iso-PTAs, 2), was divergently synthesized using an iterative sequence of palladium-catalyzedcross-coupling reactions of vinyl triflate 5 with terminalalkynes. The second series of oligoenynes (17-20) are based on an octatetrayne backbone, and result
Iterative Synthesis and Characterization of Cross-Conjugated Iso-Polydiacetylenes
作者:Yuming Zhao、Katie Campbell、Rik R. Tykwinski
DOI:10.1021/jo015810n
日期:2002.1.1
An iterative synthesis of cross-conjugated iso-polydiacetylenes (iso-PDAs) is reported based on three fundamental building blocks: vinyl triflates 8, 9, and 25. An efficient sequence of palladium-catalyzed cross-coupling reactions of vinyl triflates and terminalalkynes has been employed to extend the chain length of these oligomers. The longest member of the series, nonamer 19, spans 3.4 nm from Si
Stepwise palladium-catalyzedcross-coupling between terminalalkynes and vinyl triflates afforded the first cross-conjugated enyne macrocycles constructed of 3-alkylidene-1-propynyl [-C≡C-C(=CR2)-] building blocks, namely, the expanded radialene 1 and the hybrid radialene 2.
Charge transfer through cross-hyperconjugated versus cross-π-conjugated bridges: an intervalence charge transfer study
作者:Erik Göransson、Rikard Emanuelsson、Kjell Jorner、Todd F. Markle、Leif Hammarström、Henrik Ottosson
DOI:10.1039/c3sc50844g
日期:——
with saturated ER2 segments is highly conformer dependant. Furthermore, the calculations showed that two types of interactions contribute to the electronic coupling; a through-bond cross-(hyper)conjugation mechanism and a through-space mechanism. Taken together, these findings suggest the possibility for new architectures for molecular electronics applications utilizing cross-hyperconjugation through
近年来,通过交叉共轭分子进行电子转移和传输引起了人们极大的兴趣,作为分子和电子结构之间相互作用以及分子电子新化合物设计中潜在基序的有趣测试案例。在本文中,我们扩展了这一概念,并提出了一系列四个有机混合价二元化合物的合成和表征,以探讨桥结构对电子耦合的影响。两个三芳基胺单元之间的电子偶合可通过饱和ER 2桥(E = C或Si,R =烷基或甲硅烷基)的交叉超共轭作用或通过交叉共轭π系统。该研究的目的是将通过各种饱和桥的电子转移与交叉π共轭桥的电子转移进行比较。通过分析间隔电荷转移带确定了这些混合价化合物中的电子耦合,发现其范围为100–400 cm -1。DFT和TD-DFT的补充研究表明,饱和ER 2的二联体中的电子耦合细分是高度依从的。此外,计算表明,两种类型的相互作用有助于电子耦合。贯穿键的交叉(超)共轭机制和贯穿空间的机制。总之,这些发现表明了利用通过适当地选择饱和片段,其具有相当的电
Cross-Hyperconjugation: An Unexplored Orbital Interaction between π-Conjugated and Saturated Molecular Segments
作者:Rikard Emanuelsson、Andreas Wallner、Eugene A. M. Ng、Joshua R. Smith、Djawed Nauroozi、Sascha Ott、Henrik Ottosson
DOI:10.1002/anie.201206030
日期:2013.1.14
Crossing a barrier: Molecules with saturated ER2 units (E=C or Si, R=electron‐releasing group) inserted between two π‐conjugated segments have electronic and optical properties that resemble those of cross‐conjugated molecules (see figure). This cross‐hyperconjugation provides a deeper understanding of the conjugation phenomenon, and is an alternative to cross‐conjugation in the design of molecules