电子顺磁共振
化学
轮烷
吡啶
一氧化氮介导的自由基聚合
阳离子聚合
光化学
亚甲基
超精细结构
结晶学
超分子化学
高分子化学
分子
有机化学
核磁共振
自由基聚合
聚合物
聚合
物理
量子力学
作者
Cecilia Poderi,Iago Neira,Paola Franchi,Elisabetta Mezzina,Ilario Baù,Paolo Neviani,Marco Lucarini
标识
DOI:10.1002/chem.202301508
摘要
New nitroxides based on aza-crown ethers were prepared and employed as selective sensors for the detection of inorganic and organic cations by EPR analysis of the corresponding host-guest complexes. The nitroxide unit behaves as a sensitive probe for a number of alkali and alkaline earth metal cations affording EPR spectra differing in the value of nitrogen hyperfine constants and in the appearance of splitted signals due to the non-zero nuclear spin of some metal cation upon complexation. Owing to the remarkable EPR spectral differences between the host and the corresponding cation complex the new macrocycles are likely to act as multitasking tools to recognize several cationic species. EPR behaviour of the larger nitroxide azacrown 1⋅ when acting as a wheel in a radical synthetic bistable [2]rotaxane containing both secondary dialkylammonium and 1,2-bis(pyridinium) molecular stations, was also investigated. Reversible movements of the macrocycle between the two recognition sites in the rotaxane were promptly revealed by EPR, which shows significant changes either in nitrogen coupling constant values (aN ) or in the spectral shape in the two rotaxane co-conformations.
科研通智能强力驱动
Strongly Powered by AbleSci AI