1622237-96-0Relevant academic research and scientific papers
New short strategy for the snthesis of the dibenz[b,f]oxepins scaffold
Moreno, David R.R.,Giorgi, Giorgio,Salas, Cristian O.,Tapia, Ricardo A.
, p. 14797 - 14806 (2013)
In this report a short and efficient synthesis of the dibenz[b,f]oxepin framework through intramolecular SNAr and McMurry reactions is described. The diaryl ethers required for the McMurry reaction have been obtained in good yields under microwave-assisted conditions of the reaction of salicylaldehydes with fluorobenzaldehydes without catalysts. Application of an intramolecular McMurry reaction to the synthesized diarylethers using TiCl4/Zn in THF gave the target dibenzo[b,f]oxepin system in 53%-55% yields.
Controlling the S1energy profile by tuning excited-state aromaticity
Kotani, Ryota,Liu, Li,Kumar, Pardeep,Kuramochi, Hikaru,Tahara, Tahei,Liu, Pengpeng,Osuka, Atsuhiro,Karadakov, Peter B.,Saito, Shohei
supporting information, p. 14985 - 14992 (2020/10/13)
The shape of the lowest singlet excited-state (S1) energy profile is of primary importance in photochemistry and related materials science areas. Here we demonstrate a new approach for controlling the shape of the S1 energy profile which relies on tuning the level of excited-state aromaticity (ESA). In a series of fluorescent π-expanded oxepins, the energy decrease accompanying the bent-to-planar conformational change in S1 becomes less pronounced with lower ESA levels. Stabilization energies following from ESA were quantitatively estimated to be 10-20 kcal/mol using photophysical data. Very fast planarization dynamics in S1 was revealed by time-resolved fluorescence spectroscopy. The time constants were estimated to be shorter than 1 ps, regardless of molecular size and level of ESA, indicating barrierless S1 planarization within the oxepin series.
