Cyclo[m]pyridine[n]pyrroles: Hybrid Macrocycles That Display Expanded π-Conjugation upon Protonation
摘要:
Novel hybrid cyclo[m]pyridine[n]pyrroles have been synthesized using Suzuki coupling. Their NMR and optical spectroscopic features and solid state structural parameters provide support for the proposal that these species are best described as locally aromatic compounds devoid of long-range intersubunit conjugation. However, an extension of the pi-conjugation in the macrocycles can be realized through protonation, as inferred from optical spectroscopic and X-ray diffraction-based structural studies.
我们报告了一个完全有机的吡啶-四吡咯U型无环受体10,它在极性较小的非配位溶剂(例如CHCl 3)中更喜欢一个超分子的伪大环二聚结构(10)2。相反,当它从极性配位溶剂(例如N,N-二甲基甲酰胺,DMF)中结晶时,它表现出无穷的超分子一维(1D)“之字形”聚合物链,从单晶推断出X射线结构。该超分子系统充当强酸(例如对甲苯磺酸(PTSA),甲烷磺酸(MSA),H 2 SO 4,HNO )的潜在受体3和HCl,从浅黄色到深红色具有明显的比色响应。通过简单的水洗,可以很容易地从宿主-客体复合物的有机溶液中回收受体。观察到,相对强的酸在水中p K a <-1.92能够与受体相互作用,这是由四氢呋喃d 8(THF- d 8)和紫外可见光(UV-vis)中的1 H NMR滴定推断的298 K下无水THF中的光谱滴定。因此,这种新的动态超分子受体系统可能在材料科学研究中具有潜力。
Cyclo[6]pyridine[6]pyrrole: A Dynamic, Twisted Macrocycle with No Meso Bridges
作者:Zhan Zhang、Won-Young Cha、Neil J. Williams、Elise L. Rush、Masatoshi Ishida、Vincent M. Lynch、Dongho Kim、Jonathan L. Sessler
DOI:10.1021/ja503451m
日期:2014.5.28
A large porphyrin analogue, cyclo[6]pyridine[6]pyrrole, containing no meso bridging atoms, has been synthesized through Suzuki coupling. In its neutral form, this macrocycle exists as a mixture of two figure-eight conformers that undergo fast exchange in less polar solvents. Upon protonation, the dynamic twist can be transformed into species that adopt a ruffled planar structure or a figure-eight shape
A Hybrid Macrocycle with a Pyridine Subunit Displays Aromatic Character upon Uranyl Cation Complexation
作者:I-Ting Ho、Zhan Zhang、Masatoshi Ishida、Vincent M. Lynch、Won-Young Cha、Young Mo Sung、Dongho Kim、Jonathan L. Sessler
DOI:10.1021/ja412520g
日期:2014.3.19
Reported here is a new hybrid macrocycle, cyclo[1]furan[1]pyridine[4]pyrrole (1), that bears analogy to the previously reported mixed heterocycle system cyclo[2]pyridine[4]pyrrole (2) and cyclo[6]pyrrole 3, an all-pyrrole 22 pi-electron aromatic expanded porphyrin. The oxidized, dianionic form of 1, [1-4H](2-), has been characterized as its uranyl complex. In contrast to 2 and 3 and in spite of the presence of a 2,6-disubstituted pyridine subunit, the uranyl complex of [1-4H](2-) displays solid-state structural and solution-phase spectroscopic features consistent with contributions to the overall electronic structure that involve a conjugated, (4n + 2) pi-electron aromatic periphery.
作者:Fei Wang、Kejiang Liang、Mads Christian Larsen、Steffen Bähring、Masatoshi Ishida、Hiroyuki Furuta、Atanu Jana
DOI:10.3390/molecules26061771
日期:——
as inferred from the single-crystal X-ray structures. This supramolecular system acts as a potential receptor for strong acids, e.g., p-toluenesulfonic acid (PTSA), methane sulfonic acid (MSA), H2SO4, HNO3, and HCl, with a prominent colorimetric response from pale yellow to deep red. The receptor can easily be recovered from the organic solution of the host–guest complex by simple aqueous washing
我们报告了一个完全有机的吡啶-四吡咯U型无环受体10,它在极性较小的非配位溶剂(例如CHCl 3)中更喜欢一个超分子的伪大环二聚结构(10)2。相反,当它从极性配位溶剂(例如N,N-二甲基甲酰胺,DMF)中结晶时,它表现出无穷的超分子一维(1D)“之字形”聚合物链,从单晶推断出X射线结构。该超分子系统充当强酸(例如对甲苯磺酸(PTSA),甲烷磺酸(MSA),H 2 SO 4,HNO )的潜在受体3和HCl,从浅黄色到深红色具有明显的比色响应。通过简单的水洗,可以很容易地从宿主-客体复合物的有机溶液中回收受体。观察到,相对强的酸在水中p K a <-1.92能够与受体相互作用,这是由四氢呋喃d 8(THF- d 8)和紫外可见光(UV-vis)中的1 H NMR滴定推断的298 K下无水THF中的光谱滴定。因此,这种新的动态超分子受体系统可能在材料科学研究中具有潜力。
Cyclo[<i>m</i>]pyridine[<i>n</i>]pyrroles: Hybrid Macrocycles That Display Expanded π-Conjugation upon Protonation
作者:Zhan Zhang、Jong Min Lim、Masatoshi Ishida、Vladimir V. Roznyatovskiy、Vincent M. Lynch、Han-Yuan Gong、Xiaoping Yang、Dongho Kim、Jonathan L. Sessler
DOI:10.1021/ja211985k
日期:2012.3.7
Novel hybrid cyclo[m]pyridine[n]pyrroles have been synthesized using Suzuki coupling. Their NMR and optical spectroscopic features and solid state structural parameters provide support for the proposal that these species are best described as locally aromatic compounds devoid of long-range intersubunit conjugation. However, an extension of the pi-conjugation in the macrocycles can be realized through protonation, as inferred from optical spectroscopic and X-ray diffraction-based structural studies.