Synthesis, crystal structure, and luminescence of tetrakis(4-methoxyphenyl)methane

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• 作者：Samuel Guieu^a ; ^b ; ^sguieu@ua.pt ; Joã ; o Rocha^a ; Artur M.S. Silva^b ; ^{artur.silva@ua.pt}
• 关键词：Fluorescence ; Trityl luminophore ; Solid state luminescence ; Single X-ray crystallography ; Crystallization-induced phosphorescence
• 刊名：Tetrahedron Letters
• 出版年：2013
• 出版时间：29 May, 2013
• 年：2013
• 卷：54
• 期：22
• 页码：2870-2873
• 全文大小：781 K

文摘

A new synthesis of a tetrahedral tecton, tetrakis(4-methoxyphenyl)methane, is reported. This compound exhibits a strong fluorescence around 340 nm at room temperature, both in solution and in the solid state. Upon crystallization, another luminescence band can be observed around 500 nm, attributed to phosphorescence. A study of the single-crystal structure of the compound provided a rationalization of this crystallization induced phosphorescence. The crystal of tetrakis(4-methoxyphenyl)methane belongs to the tetragonal space group P2₁c, and the structural analysis revealed a close packing of the molecules, with no void space and no solvent molecules in the crystal. The molecules are held together in a columnar array via multiple C-H?¦Ð hydrogen bonds. The hydrogen bonds between the molecules impede the torsional vibrations of the aromatic rings, preventing thermal relaxation from the triplet state, and hence promoting phosphorescence at room temperature.