Novel Photoswitchable Receptors: Synthesis and Cation-Induced Self-Assembly into Dimeric Complexes Leading to Stereospecific [2+2]-Photocycloaddition of Styryl Dyes Containing a 15-Crown-5 Ether Unit
摘要:
Styryl dyes 4a-e containing a 15-crown-5 ether unit and a quinoline residue with a sulfonatoalkyl or sulfonatobenzyl N-substituent were synthesized. The relationship between the photochemical behavior of these dyes and their aggregates derived from complexation with Mg2+ in MeCN was studied using H-1 NMR and absorption spectroscopy. The E-isomers of 4a-e were shown to form highly stable dimeric (2:2) complexes with Mg2+. Upon irradiation with visible light, the dimeric complexes undergo two competing photoreactions, viz., geometric E --> Z isomerization, resulting in an anion-capped 1:1 complex of the Z-isomer with Mg2+ and stereospecific syn-head-to-tail [2+2]-cycloaddition, affording a single isomer of bis-crown-containing cyclobutane. The N-substituent in the dye has a dramatic effect on the photochemical behavior of the dimeric complex. Molecular dynamics and semiempirical quantum-chemical calculations were carried out to interpret the observed photocycloaddition in the dimer. Conformational equilibria for the dimer of (E)-4b were analyzed using H-1 NMR spectroscopy.
Synthesis and structures of azine-based crown-containing hetarylphenylethenes
作者:E. N. Andryukhina、M. M. Mashura、O. A. Fedorova、L. G. Kuz'mina、J. A. K. Howard、S. P. Gromov
DOI:10.1007/s11172-006-0025-5
日期:2005.7
Condensation of methyl-substituted six-membered heteroaromatics containing one or two nitrogen atoms with aldehyde derived from benzo-15-crown-5 ether in DMF in the presence of ButOK afforded 15-crown-5-containing hetarylphenylethenes. According to the results of NMR spectroscopy, these compounds exist as mixtures of syn and anti conformers in solution (MeCN-d3). The structures of two compounds were established by X-ray diffraction analysis.
甲基取代的含一个或两个氮原子的六元杂芳香族化合物与苯并-15-冠醚衍生的醛在 DMF 和 ButOK 的存在下缩合,得到了含有 15-冠-5-的 hetarylphenylethenes。根据核磁共振光谱的结果,这些化合物在溶液(MeCN-d3)中以同构和反构的混合物形式存在。通过 X 射线衍射分析确定了两种化合物的结构。
Novel Photoswitchable Receptors: Synthesis and Cation-Induced Self-Assembly into Dimeric Complexes Leading to Stereospecific [2+2]-Photocycloaddition of Styryl Dyes Containing a 15-Crown-5 Ether Unit
作者:Sergey P. Gromov、Evgeny N. Ushakov、Olga A. Fedorova、Igor I. Baskin、Alexei V. Buevich、Elena N. Andryukhina、Michael V. Alfimov、Dan Johnels、Ulf G. Edlund、James K. Whitesell、Marye Anne Fox
DOI:10.1021/jo034460x
日期:2003.8.1
Styryl dyes 4a-e containing a 15-crown-5 ether unit and a quinoline residue with a sulfonatoalkyl or sulfonatobenzyl N-substituent were synthesized. The relationship between the photochemical behavior of these dyes and their aggregates derived from complexation with Mg2+ in MeCN was studied using H-1 NMR and absorption spectroscopy. The E-isomers of 4a-e were shown to form highly stable dimeric (2:2) complexes with Mg2+. Upon irradiation with visible light, the dimeric complexes undergo two competing photoreactions, viz., geometric E --> Z isomerization, resulting in an anion-capped 1:1 complex of the Z-isomer with Mg2+ and stereospecific syn-head-to-tail [2+2]-cycloaddition, affording a single isomer of bis-crown-containing cyclobutane. The N-substituent in the dye has a dramatic effect on the photochemical behavior of the dimeric complex. Molecular dynamics and semiempirical quantum-chemical calculations were carried out to interpret the observed photocycloaddition in the dimer. Conformational equilibria for the dimer of (E)-4b were analyzed using H-1 NMR spectroscopy.