- Why Do Simple Molecules with "isolated" Phenyl Rings Emit Visible Light?
-
π-Bonds connected with aromatic rings were generally believed as the standard structures for constructing highly efficient fluorophores. Materials without these typical structures, however, exhibited only low fluorescence quantum yields and emitted in the ultraviolet spectral region. In this work, three molecules, namely bis(2,4,5-trimethylphenyl)methane, 1,1,2,2-tetrakis(2,4,5-trimethylphenyl)ethane, and 1,1,2,2-tetraphenylethane, with nonconjugated structures and isolated phenyl rings were synthesized and their photophysical properties were systematically investigated. Interestingly, the emission spectra of these three molecules could be well extended to 600 nm with high solid-state quantum yields of up to 70%. Experimental and theoretical analyses proved that intramolecular through-space conjugation between the "isolated" phenyl rings played an important role for this abnormal phenomenon.
- Zhang, Haoke,Zheng, Xiaoyan,Xie, Ni,He, Zikai,Liu, Junkai,Leung, Nelson L. C.,Niu, Yingli,Huang, Xuhui,Wong, Kam Sing,Kwok, Ryan T. K.,Sung, Herman H. Y.,Williams, Ian D.,Qin, Anjun,Lam, Jacky W. Y.,Tang, Ben Zhong
-
p. 16264 - 16272
(2017/11/22)
-
- An efficient synthesis of diarylmethanes via InCl3*4H2O-catalyzed dehydration of electron-rich arenes with trioxane
-
A facile, efficient and environmentally benign procedure for the synthesis of diarylmethanes via the reaction of arenes with trioxane catalyzed by InCl3*4H2O was developed. The reactions of aromatic compounds bearing electron-donating group proceeded smoothly affording the corresponding diarylmethanes in good to excellent yields.
- Sun, Hong-Bin,Hua, Ruimao,Yin, Yingwu
-
p. 2291 - 2294
(2007/10/03)
-
- Mechanism of Oxidation of Methylbenzenes by Palladium(II) in Trifluoroacetic Acid. One-electron Transfer and Electrophilic Substitution
-
The oxidation of methylbenzenes by Pd(II) in CF3CO2H to give diarylmethanes has been shown to occur via a one-electron transfer mechanism.
- Kozhevnikov, Ivan V.,Kim, Vladimir I.,Talzi, Eugeni P.,Sidelnikov, Vladimir N.
-
p. 1392 - 1394
(2007/10/02)
-
- SYNTHESIS OF SUBSTITUTED 2,4,5-TRIMETHYLDIPHENYLMETHANES
-
2,5-Dimethyldiphenylmethane and its 2'- and 4'-methyl, chloro, and nitro derivatives were obtained by the reaction of substituted benzyl chlorides with p-xylene in the presence of ferric chloride and zinc stearate.The yields of the 2,5-dimethyldiphenylmethanes depend on the nature of the substituent in the benzyl chloride and decrease with the substituents in the order NO2>Cl>H>CH3.The 2' and 4'-methyl, chloro, and aminoderivatives of 2,4,5-trimethyldiphenylmethane were synthesized by chloromethylation of the obtained diphenylmethanes with paraform in acetic acid in the presence of zinc chloride followed by reduction of the 2,5-dimethyl-4-chloromethyldiphenylmethanes with zinc in acetic acid.
- Pozdnyakovich, Yu. V.,Borodovitsyn, V. V.,Pozdnyakovich, S. A.,Shein, S. M.
-
p. 353 - 359
(2007/10/02)
-