Spectroscopic and theoretical studies of acid-base behaviors of n-confused porphyrins: Effects of meso -aryl substituents

Ryuichi Sakashita, Masatoshi Ishida, Hiroyuki Furuta

研究成果: ジャーナルへの寄稿学術誌査読

23 被引用数 (Scopus)

抄録

The acid-base properties of a series of meso-aryl-substituted N-confused porphyrins (NCPs) were examined in aqueous sodium dodecyl sulfate (SDS) micellar solutions by both spectrophotometric methods and theoretical calculations. Reflecting the unsymmetrical structure of NCP having an outward-pointing pyrrolic nitrogen atom, the first and second protonations were distinguishable in the absorption and 1H NMR spectra, unlike for porphyrins, and the pK3 and pK4 values were determined discretely. The individual basicities of the NCPs were directly related to the inductive effect of para substituents on the meso-phenyl groups: A linear relationship between the pK3 (pK4) and Hammett σpara parameters was revealed. In the case of deprotonation, the structure of monoanionic NCP species was similarly characterized by the absorption and 1H NMR spectra. For the second deprotonation, the pK1 value was determined to be 11.39 for the NCP derivative with pentafluorophenyl groups. DFT calculations support the changes in electronic structures and aromaticity of the cationic and anionic species. It is demonstrated that NCPs are easily protonated and deprotonated compared to the corresponding regular congeners.

本文言語英語
ページ(範囲)1013-1022
ページ数10
ジャーナルJournal of Physical Chemistry A
119
6
DOI
出版ステータス出版済み - 2月 12 2015

!!!All Science Journal Classification (ASJC) codes

  • 物理化学および理論化学

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