Institute of Physical Chemistry, Polish Academy of Sciences , 01-224 Warsaw, Kasprzaka 44/52, Poland.
Faculty of Mathematics and Science, Cardinal Stefan Wyszyński University , Dewajtis 5, 01-815 Warsaw, Poland.
Chem Rev. 2017 Feb 22;117(4):2447-2480. doi: 10.1021/acs.chemrev.6b00328. Epub 2016 Jul 28.
Tautomerization in porphycenes, constitutional isomers of porphyrins, is strongly entangled with spectral and photophysical parameters. The intramolecular double hydrogen transfer occurring in the ground and electronically excited states leads to uncommon spectroscopic characteristics, such as depolarized emission, viscosity-dependent radiationless depopulation, and vibrational-mode-specific tunneling splittings. This review starts with documentation of the electronic spectra of porphycenes: Absorption and magnetic circular dichroism are discussed, together with their analysis based on the perimeter model. Next, photophysical characteristics are presented, setting the stage for the final part, which discusses the developments in research on tautomerism. Porphycenes have been studied in different experimental regimes: molecules in condensed phases, isolated in supersonic jets and helium nanodroplets, and, recently also on the level of single molecules investigated by optical and scanning probe microscopies. Because of the rich and detailed information obtained from these diverse investigations, porphycenes emerge as very good models for studying the complex, multidimensional phenomena involved in the process of intramolecular double hydrogen transfer.
并五苯，卟啉的结构异构体，其互变异构强烈地与光谱和光物理参数纠缠在一起。在基态和电子激发态中发生的分子内双氢转移导致了不寻常的光谱特征，如去偏振发射、与粘度相关的非辐射衰减以及振动模式特异性隧道分裂。本综述首先记录了并五苯的电子光谱：讨论了吸收和磁圆二色性，并结合周长模型对其进行了分析。接下来，介绍了光物理特性，为最后一部分讨论互变异构的研究进展奠定了基础。在不同的实验条件下研究了并五苯：凝聚相中分子、在超声射流和氦纳米液滴中分离的分子，以及最近在光学和扫描探针显微镜研究的单分子水平上研究的分子。由于从这些不同的研究中获得了丰富而详细的信息，因此并五苯成为研究涉及分子内双氢转移的复杂多维现象的非常好的模型。
