...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of spectroscopy >Effects of Core and/or Peripheral Protonation ofmeso-Tetra(2-, 3-, and 4-pyridyl)Porphyrin andmeso-Tetra(3-methylpyridyl)Porphyrin on Their UV-vis Spectra
【24h】

Effects of Core and/or Peripheral Protonation ofmeso-Tetra(2-, 3-, and 4-pyridyl)Porphyrin andmeso-Tetra(3-methylpyridyl)Porphyrin on Their UV-vis Spectra

机译：中四（2-，3-和4-吡啶基）卟啉和中四（3-甲基吡啶基）卟啉的核心和/或外围质子化对其紫外-可见光谱的影响

获取原文
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Core and/or peripheral protonation ofmeso-tetra(pyridyl)porphyrins, H2(py)P, with weak and strong acids have been studied by UV-vis spectroscopy. The results support the proposal that the position of the Soret as well as the Q(0,0) bands of the dications is influenced byπdonation from themesosubstituents to the porphyrin core. The red shift of the Q(0,0) band of H2t(py)P dications with 2-, 3-, and 4-pyridyl substituents does not correlate with the order ofπelectron donor ability of themesogroups. The decreased electron donation from the central nitrogen atoms to the acids on going from 3-pyridyl group to 4- and 2-pyridyl ones has been used to explain this observation. In spite of the negative effect of N-methylation of pyridyl substituents on the basicity of the central nitrogen atoms ofmeso-tetra(3-methylpyridyl)porphyrin, H2t(3-Mepy)P, protonation of H2t(3-Mepy)P occurs with weak and strong acids. The blue shift of the Q(0,0) bands upon protonation of H2t(3-Mepy)P with weak and strong acids clearly shows the importance of resonance interactions between theπ-systems of porphyrin and the aryl substituents on the position of the band.
机译：通过紫外-可见光谱研究了间-四（吡啶基）卟啉，H2（py）P，弱和强酸的核心和/或外围质子化。结果支持了这样的建议，即药物的Soret以及Q（0,0）谱带的位置受主题取代基向卟啉核心的π捐赠影响。具有2-，3-和4-吡啶基取代基的H2t（py）P药物的Q（0,0）带的红移与主题基团的π电子给体能力的顺序不相关。从中心氮原子到酸的电子给体从3-吡啶基变成4-和2-吡啶基的电子给体减少已被用来解释这一观察结果。尽管吡啶基取代基的N-甲基化对间-四（3-甲基吡啶基）卟啉，H2t（3-Mepy）P的中心氮原子的碱性有负面影响，但H2t（3-Mepy）P的质子化仍弱酸和强酸。用弱酸和强酸使H2t（3-Mepy）P质子化时Q（0,0）谱带的蓝移清楚地表明了卟啉π系统与谱带位置上的芳基取代基之间共振相互作用的重要性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号