104292-54-8Relevant academic research and scientific papers
Precise control of π-electron magnetism in metal-free porphyrins
Guan, Dandan,Jia, Jinfeng,Jiang, Kaiyue,Li, Can,Li, Yaoyi,Liu, Yufeng,Luo, Weidong,Wang, Shiyong,Xu, Chengyang,Zhao, Yan,Zheng, Hao,Zheng, Wenna,Zhuang, Xiaodong
, p. 18532 - 18540 (2020)
The porphyrin macrocycle can stabilize a set of magnetic metal ions, thus introducing localized net spins near the center. However, it remains elusive but most desirable to introduce delocalized spins in porphyrins with wide implications, for example, for
Inducing Open-Shell Character in Porphyrins through Surface-Assisted Phenalenyl π-Extension
Bottari, Giovanni,Fasel, Roman,Lorente, Nicolas,Mateo, Luis M.,Robles, Roberto,Ruffieux, Pascal,Sun, Qiang,Torres, Tomás
supporting information, p. 18109 - 18117 (2020/11/26)
Organic open-shell compounds are extraordinarily attractive materials for their use in molecular spintronics thanks to their long spin-relaxation times and structural flexibility. Porphyrins (Pors) have widely been used as molecular platforms to craft persistent open-shell structures through solution-based redox chemistry. However, very few examples of inherently open-shell Pors have been reported, which are typically obtained through the fusion of non-Kekulé polyaromatic hydrocarbon moieties to the Por core. The inherent instability and low solubility of these radical species, however, requires the use of bulky substituents and multistep synthetic approaches. On-surface synthesis has emerged as a powerful tool to overcome such limitations, giving access to structures that cannot be obtained through classical methods. Herein, we present a simple and straightforward method for the on-surface synthesis of phenalenyl-fused Pors using readily available molecular precursors. In a systematic study, we examine the structural and electronic properties of three surface-supported Pors, bearing zero, two (PorA2), and four (PorA4) meso-fused phenalenyl moieties. Through atomically resolved real-space imaging by scanning probe microscopy and high-resolution scanning tunneling spectroscopy combined with density functional theory calculations, we unambiguously demonstrate a triplet ground state for PorA2 and a charge-transfer-induced open-shell character for the intrinsically closed-shell PorA4.
Effects of aldehyde or dipyrromethane substituents on the reaction course leading to meso-substituted porphyrins
Geier III, G. Richard,Lindsey, Jonathan S.
, p. 11435 - 11444 (2007/10/03)
To better understand the effects of diverse substituents on reactions leading to porphyrins, pyrrole+aldehyde condensations and related reactions of dipyrromethanes were examined. The course of pyrrole+aldehyde condensations was investigated by monitoring the yield of porphyrin (by UV-Vis spectroscopy), reaction of aldehyde (by TLC), and changes in the composition of oligomers (by laser desorption mass spectrometry). Reaction reversibility was examined via exchange experiments. Reversibility of reactions leading to porphyrin was further probed with studies of dipyrromethanes. The reaction course was found to depend on the nature of the substituent and the acid catalyst. Alkyl or electron-donating substituents displayed levels of reversibility (exchange/scrambling) on par or greater than that of the phenyl substituent, whereas electron-withdrawing or sterically bulky substituents exhibited little to no reversibility. The results obtained provide insight into the electronic and steric effects of different substituents and should facilitate the design of synthetic plans for preparing porphyrinic macrocycles. Graphical abstract.
IMROVED METHOD FOR SYNTHESIS OF SUBSTUTUTED TETRAPHENYLPORPHINS
Semeikin, A. S.,Koifman, O. I.,Berezin, B. D.
, p. 629 - 632 (2007/10/02)
Condensation of pyrrole with benzaldehydes in a mixture of xylene and chloroacetic acid gives a series of substituted tetraphenylporphins with yields exeeding the yields of porphyrins synthetized according to known preparative methods.
