低温基质中分离的吲哚和 3-甲酰吲哚单体的光诱导转化。

Photoinduced transformations of indole and 3-formylindole monomers isolated in low-temperature matrices.

机构信息

CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.

Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.

出版信息

J Chem Phys. 2017 Nov 21;147(19):194304. doi: 10.1063/1.5003326.

DOI:10.1063/1.5003326

PMID:29166121

Abstract

Photochemical transformations were studied for monomers of indole and 3-formylindole isolated in low-temperature noble-gas matrices. Upon UV (λ > 270 nm) irradiation of indole trapped in argon and neon matrices, the initial 1H-form of the compound converted into the 3H-tautomer. Alongside this photoinduced hydrogen-atom transfer, an indolyl radical was also generated by photodetachment of the hydrogen atom from the N1-H bond. Excitation of 3-formylindole isolated in an argon matrix with UV (λ > 335 nm) light led to interconversion between the two conformers of the 1H-tautomer, differing from each other in the orientation of the formyl group (cis or trans). Parallel to this conformational phototransformation, the 3H-form of the compound was generated in the 1H → 3H phototautomeric conversion. The photoproducts emerging upon UV irradiation of indole and 3-formylindole were identified by comparison of their infrared spectra with the spectra calculated for candidate structures.

摘要

光化学转化研究了吲哚和 3-甲酰基吲哚单体在低温稀有气体基质中的分离。在氩气和氖基质中捕获的吲哚的紫外线（λ＞270nm）辐照下，化合物的初始 1H 形式转化为 3H 互变异构体。除了这种光诱导的氢原子转移外，通过从 N1-H 键光解氢原子也产生了吲哚基自由基。用紫外线（λ＞335nm）激发在氩气基质中分离的 3-甲酰基吲哚导致 1H 互变异构体的两种构象之间的互变，它们在甲酰基的取向（顺式或反式）上彼此不同。与这种构象光转化平行，在 1H→3H 光互变异构转化中生成了化合物的 3H 形式。通过将红外光谱与候选结构的计算光谱进行比较，鉴定了吲哚和 3-甲酰基吲哚经紫外线照射产生的光产物。