The SnCl2 reduction of 2-nitrocyclododecanone or 2-bromo-12-nitrocyclododecanone gave a colorless compound 2,3,5,6-bis(ortho-1,10-decylidene)dihydropyrazine 1a characterized by IR, NMR and X-ray diffraction analysis...The SnCl2 reduction of 2-nitrocyclododecanone or 2-bromo-12-nitrocyclododecanone gave a colorless compound 2,3,5,6-bis(ortho-1,10-decylidene)dihydropyrazine 1a characterized by IR, NMR and X-ray diffraction analysis. Crystal data for 1a: Mr = 358.60, monoclinic, space group P2 1/n, α = 0.48028(3), b = 2.8646(4), c = 0.77097(6) nm, β = 98.432(12)°, V = 1.04924(19) nm^3, Dc = 1.135 g/cm^3, Z = 2, F(000) = 400 and μ(MoKa) = 0.065 mm^-1. All ^1H- and ^13C-NMR resonance lines of 1a were assigned by DEPT, COSY, HMQC and HMBC technology. In the crystal, the dihydropyrazine ring has a planar structure, two twelve-membered tings adopt [lene2333] conformation, their double bonds have cis-configuration, and the whole molecule has a center of symmetry. In solution, the symmetric ^1H- and ^13C-NMR signals suggest that two twelve-membered rings of 1a may adopt enantiomorphous [ lene2333] conformation existing in a dynamic equilibrium.展开更多
Organic fluorophores with dynamic conformations in the excited state have played a significant role in applications of organic functional dyes.Among them,dihydrophenazine-based dynamic fluorophores involving a photoin...Organic fluorophores with dynamic conformations in the excited state have played a significant role in applications of organic functional dyes.Among them,dihydrophenazine-based dynamic fluorophores involving a photoinduced structural planarization process in the excited state exhibited large Stokes shifts and conformation-dependent multicolor emissions.With the developments of synthetic strategies,precise modifications on dihydrophenazinebased scaffolds have successfully afforded a variety of precise molecular structures of varying sizes and compositions,which have delicately modulated their photophysical properties.Herein,this Perspective summarizes the precise modulations of dihydrophenazine-based dynamic fluorophores,including the development of the synthetic methodologies,and tailor-made molecular models to reveal the luminescence−structure relationships.展开更多
基金This project was supported by the National Natural Science Foundation of China (No. 20072053)
文摘The SnCl2 reduction of 2-nitrocyclododecanone or 2-bromo-12-nitrocyclododecanone gave a colorless compound 2,3,5,6-bis(ortho-1,10-decylidene)dihydropyrazine 1a characterized by IR, NMR and X-ray diffraction analysis. Crystal data for 1a: Mr = 358.60, monoclinic, space group P2 1/n, α = 0.48028(3), b = 2.8646(4), c = 0.77097(6) nm, β = 98.432(12)°, V = 1.04924(19) nm^3, Dc = 1.135 g/cm^3, Z = 2, F(000) = 400 and μ(MoKa) = 0.065 mm^-1. All ^1H- and ^13C-NMR resonance lines of 1a were assigned by DEPT, COSY, HMQC and HMBC technology. In the crystal, the dihydropyrazine ring has a planar structure, two twelve-membered tings adopt [lene2333] conformation, their double bonds have cis-configuration, and the whole molecule has a center of symmetry. In solution, the symmetric ^1H- and ^13C-NMR signals suggest that two twelve-membered rings of 1a may adopt enantiomorphous [ lene2333] conformation existing in a dynamic equilibrium.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.21790361 and 21871084)Shanghai Municipal Science and Technology Major Project(Grant No.2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universities,the Programme of Introducing Talents of Discipline to Universities(Grant No.B16017)Program of Shanghai Academic/Technology Research Leader(19XD1421100)the Shanghai Science and Technology Committee(Grant No.17520750100)the China Postdoctoral Science Foundation(2020M671018).
文摘Organic fluorophores with dynamic conformations in the excited state have played a significant role in applications of organic functional dyes.Among them,dihydrophenazine-based dynamic fluorophores involving a photoinduced structural planarization process in the excited state exhibited large Stokes shifts and conformation-dependent multicolor emissions.With the developments of synthetic strategies,precise modifications on dihydrophenazinebased scaffolds have successfully afforded a variety of precise molecular structures of varying sizes and compositions,which have delicately modulated their photophysical properties.Herein,this Perspective summarizes the precise modulations of dihydrophenazine-based dynamic fluorophores,including the development of the synthetic methodologies,and tailor-made molecular models to reveal the luminescence−structure relationships.