Research group of Professor Song Jianxin of Hunan Normal University: synthesis and structural characterization of a new type of extended ring porphyrin smaragdyrin

Because of its unique structure, special physical and chemical properties, the introduction extended ring porphyrin has been widely concerned On the one hand, it has the variability in space and electronic structure, which makes it an ideal model compound to study the aromaticity transformation and aromaticity anti aromaticity transformation of shool Mobius On the other hand, it is a good framework to stabilize free radicals In addition, the unique chemical structure of the extended ring porphyrin endows it with unique optical properties, which makes it have potential applications in photodynamic therapy, nonlinear optical materials and so on Recently, Professor Song Jianxin's research group of Hunan Normal University has made a new breakthrough in this field Relevant research results were published in J am Chem SOC (DOI: 10.1021 / JACS 8b07973) Brief introduction of Professor Song Jianxin's research group Professor Song Jianxin has been working on porphyrin chemistry since he joined Hunan Normal University in September 2011 Their interests are focused on the design, synthesis, properties and related supramolecular chemistry of porphyrins Many of these functional molecules have novel structure and some absorption in the near infrared region, so they have the potential to be used in photodynamic therapy Since 2014, the research team has made a series of research results in this field (angel Chem Int ed 2017, 56, 12322; org Lett 2017, 19, 2654; chem Commun 2017, 53, 11488; angel Chem Int ed 2016, 55, 6438; chem EUR J 2016, 22, 8801; chem EUR J 2015, 21, 15328; angel Chem Int ed 2014, 53, 11088) This indicates that Hunan Normal University has been at the international forefront in the design, synthesis and Performance Research of porphyrin functional molecules Prof song Jianxin, Professor of Hunan Normal University, doctoral supervisor, vice president of School of chemical engineering He graduated from the school of chemistry and chemical engineering of Hunan Normal University in 1996 and 1999 respectively In 1999, he was admitted to Hunan University for his doctoral degree In 2002, he visited the University of Florida in the United States In 2006, he was supported by the National Scholarship Council and went to Kyoto University for postdoctoral research After that, he studied in Japan and returned to Hunan Normal University to teach in 2011 It has been supported by the National Natural Science Foundation of China, the research start-up fund for returned students of the Ministry of education, the innovation platform project of colleges and universities in Hunan Province, the discipline leader cultivation project of colleges and universities in Hunan Province, and the talent introduction project of Hunan Normal University Leading scientific research achievements: synthesis and structural characterization of a novel ring expanding porphyrin, smaragdyrin, which was predicted to exist as early as 1960s For more than half a century, although there have been some studies on its analogues from time to time, no literature has reported the synthesis and structural characterization of total nitrogen smaragdyrin before the work of this paper This is mainly because the total nitrogen smaragdyrin is very unstable and easy to be oxidized in the air, so its separation and characterization are very difficult Fig 1 Crystal structure (top view and side view) of compounds 3 (a, b), 4 (C, d), 5 (E, f) (source: J am Chem SOC.) using tripyrrole methane and dibromo BODIPY as raw materials, in the presence of alkali, the stable aromatic macrocyclic compound 3 is formed by aromatic nucleophilic substitution into ring dehydrogenation 3 can be further oxidized to form an anti aromatic macrocyclic compound 4 The aromatic macrocyclic compound 3 is very unstable after debonding, and it is easy to turn into Anti aromatic macrocyclic compound 5 The aromatic macrocyclic compound 6 can be obtained by reduction in inert atmosphere The boron containing aromatic compound 3 is more stable than the anti aromatic compound 4, but the de Boron anti aromatic compound 5 is more stable than the aromatic compound 6 Fig 2 UV-vis-NIR absorption spectra of compounds 3, 4, 5 and 6 (source: J am Chem SOC.) the author further studied the UV-vis-NIR absorption spectra of compounds 3, 4, 5 and 6 (Fig 2) There are two peaks in the UV-vis-NIR absorption spectra of compounds 3 and 6, i.e Soret band and Q band The absorption peaks of compounds 4 and 5 are totally different They show a wide absorption peak at 376-600 nm and a very wide absorption peak in the near infrared region The above results show that 3 and 6 are aromatic compounds, while 4 and 5 are anti aromatic compounds In addition, the aromaticity of the compounds was studied by density functional method, and the nuclear independent chemical shifts (NICS) of the compounds were calculated The results of these calculations are consistent with the experimental results, further proving the aromaticity / anti aromaticity of these compounds (part of computational chemistry was completed by Professor Liu Shubin and his doctoral student Yu Donghai) The unique structure of these compounds makes them have potential applications in host guest chemistry and aromaticity anti aromaticity reversal The experimental part of the thesis is mainly completed by Xie Daguan, Liu Yang, master's degree candidate and Rao Yutao, doctoral degree candidate Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeangoapp, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.