RESUMO
A metal-free and thiol-free organophosphorus-catalyzed method for forming thioethers was disclosed, driven by PIII/PVâO redox cycling. In this work, one-step dehydroxylative thioetherification of alcohols was fulfilled with various hypervalent organosulfur compounds. This established strategy features an excellent functional group tolerance and broad substrate scope, especially inactivated alcohols. The scale-up reaction and further transformation of the product were also successful. Additionally, this method offers a protecting-group-free and step-efficient approach for synthesizing peroxisome proliferator-activated receptor agonists which exhibited promising potential for treating osteoporosis in mammals.
RESUMO
Tm3+, Ho3+, Yb3+ co-doped YPO4 micro-nano tubes were synthesized by hydrothermal method. Under the 980 nm near infrared (NI) excitation, the micro-nano tubes emitted red, green, blue visible light and a near infrared emission centered at 795 nm. The optical properties and structure of the synthesized Tm3+, Ho3+, Yb3+ co-doped YPO4 micro-nano tubes were characterized by testing the TEM, XRD and fluorescence spectra. The results showed that the micro-nano tubes are pure hexagonal phase. The hydrothermal temperature had obvious effect on fluorescence spectra but little effect on phase. The intensity of the emission peaks didn't increase with the concentration of doping ions monotonously under the same reaction temperature, but changed non-monotonously due to the concentration quenching and cross relation. The possible upconversion (UC) mechanism was discussed in this paper. This UC emission intensity controllable fluorescent material has potential application in three dimension solid display, UC illumination, fluorescence detection and some other fields.