Study on the Heteroatom Influence in Pyridine-Based Nitronyl Nitroxide Biradicals with Phenylethynyl Spacers on the Molecular Ground State
作者:Chandrasekar Rajadurai、Anela Ivanova、Volker Enkelmann、Martin Baumgarten
DOI:10.1021/jo034597n
日期:2003.12.1
were synthesized and investigated by ESR and UV-vis spectroscopy. The solution EPR measurements of the biradicals gave well-resolved, nine-line spectra with exact half line spacing as compared to monoradicals (giso = 2.0067) with isotropic line spacing /aN/= 7.36 G. This indicates strong, intramolecular exchange coupling (J >> 7 x 10(-4) cm(-1); J/aN >> 1) of the biradicals with in the limit of EPR
新型的吡啶基硝化基氮氧化物(NIT)双自由基,3,5-双[4-(1-氧代-3-氧代-4,4,5,5-四甲基咪唑啉-2-基)苯基乙炔基)]吡啶e(1)和2,6-双[4-(1-氧代-3-氧代-4,4,5,5-四甲基咪唑啉-2-基)苯基乙炔基)]吡啶e(2)和单基4-(5-溴吡啶-3-ylethynyl)-1-(1-oxyl-3-oxo-4,4,5,5-tetramethylimidazolin-2-yl)苯(3),4-三甲基甲硅烷基乙炔基-1-(1-oxyl-3-oxo -4,4,5,5-四甲基咪唑啉-2-基)(4)和4-三甲基甲硅烷基乙炔基-1-(1-氧基-3-氧代-4,4,5,5-四甲基咪唑啉-2-基吡啶(5)的合成,并通过ESR和紫外可见光谱研究。双自由基的溶液EPR测量得到分辨率良好的九线光谱,与等距各向同性线间距/ aN / = 7.36 G的单自由基(giso = 2.0067)相