SU480743A1 - The method of obtaining 2, 5, 2, 5-tetramethyl-2, 3, 5, 6-tetrafluoro-p-quinquiphenyl - Google Patents

Description

one

This invention relates to a method for producing a new luminescent compound — 2i, 5.2, 5-tetramethyl-2 3 5 6 -tetrafluoro-p-quinquiphenyl, which can be used as a luminescent substance in the manufacture of high-speed scintillators and for creating special scintillation detectors fast peitrons.

A known method for preparing 2,51,2,55-tetramethyl-p-quinquiphenyl by reacting 4,4 diiodo-l-terphenyl with 2-iodoparaxylene in the presence of bi-l-xylyl.

The known luminescent compound has the following luminescent characteristics in a dioxane solution (mol / l); Yamax absorption, them

(3,104 mol mol-1 cm-1) 300

Yamax emission, nm373

T) quantum yield0.95

t luminescence time (upon photoexcitation of the additive itself), HC1.4.

In order to simultaneously preserve the luminescent properties and reduce the luminescence time of the luminescent compound, a method has been proposed for producing a new luminescent compound — 2.5 2; 5-t: egi and tl-2,3., 5; tetrafluoro-quiquiphenyl — 4,4-diode interaction -2,3,51,6-tetrafluoro-interphN1 with 2-iodine - "- xylene in the presence of bixylil and mercury-activated copper catalyst.

The presence in the target product of a fluorine atom in the central phenyl ring allowed

significantly reduce the time of exposure, to expand the scope of the target product.

PRI me R 4,4-Diyod-2,31,5,61-phenyl tetrafluorter.

In a three-necked flask equipped with a reflux condenser and mechanical stirrer, 50 ml of glacial acetic acid, 50 ml of nitrobenzene and 5 g 2,, 6 of tetrafluorothenyl, are heated, the reaction mixture is heated to

At a temperature of 80 ° C, 10 ml of water, 10 ml of sulfuric acid, 4.2 g of iodine (freshly boiled), 8.5 g of iodic acid and 3.5 ml of carbon tetrachloride are added with vigorous stirring. Heat for 30 h.

The flasks are cooled, the precipitate is filtered off with suction, washed with acetic acid, plenty of hot water, alcohol and air dried. Get 3 g (about 40%) and product with a pinkish tinge, so pl.

274-278 ° C.

Recrystallized from benzene with precipitation with methyl alcohol (1: 1), and then subjected to fractionated vacuum sublimation (residual pressure 3-10 mm

Hg Art.). The fraction that is distilled at 150 ° C (about 2.3 g) is recrystallized from benzene with methyl alcohol. Obtain 1.5 g (about 16%) of the product, so pl. 293-298 ° C. Found,%: C 39.18; 39.14; H 1.60; 1.58. F 12,57,12,65; 146.38, 46.12. C 8H8P412. Calculated,%: C 39.00; H 1.44; F 13.72; I 45.84. 2l, 5 2 5 -Tetramethyl-2 3 5 6 -tetraptop-lcvncvnphenyl. In a two-neck flask equipped with a mechanical stirrer and a hydraulic shutter, 17 g of 2-iodo-l-xylene, 4 g of 4,4 -diodo 3, 2 5 61-tetrafluorophenyl, 20.5 g of copper powder (freshly activated), two drops of mercury and 5 g bixillus. Under nitrogen, stirring, the reaction mixture is heated at 200 ° C for 2 hours, then at 220 ° C - 2 hours and at 240 ° C - 2 hours, the temperature is raised to 260 ° C, kept for 0.5 hours. extracted with toluene in the Soxhlet apparatus (about 11 hours). The toluene is distilled off, the remaining product is washed with hot alcohol, and air dried. Yellowish product, 3.1 g (84%). Dissolved in toluene, chromatographed over alumina, recrystallized from toluene to methyl alcohol. It is then sublimated under vacuum. After sublimation, rechromatograph. Get white crystalline product, 1 g (29%), so pl. 214-218 ° C. Found,%: C 80.40, 80.34; H 5.17, 5.00; F 15.24. C34H26F4. Calculated,%: C 80.00; H 5.10; F 14.90. The luminescence characteristics of this compound in dioxane solution are as follows (mol / l): VaKc absorption, nm (, 65-10 l-mol-1-CM-i) 280 Yamax emission, nm365 T) quantum yield 0.90 t flash time (during photoexcitation additive itself) HC1.20. Subject of the invention. Method of preparation, 5-tetramethyl-2h, 3h, 5.6 -tetrafluoro -quinquiphenyl, characterized in that, in order to simultaneously preserve the luminescent properties and reduce the decay time, 4,4 -diodo; terphenyl is borrowed with 2-iodine-p-xylene in the presence of bixylil and a mercury-activated catalyst followed by separation of the target product by known methods.