Manganese difluoride

When subjected to high temperatures and pressures, polymorphs have been prepared for some of the difluorides. These all have distorted variants of the fluorite structure, with cubic, or pseudocubic, tetragonal cells. Manganese difluoride has been most studied (28-30) and similar polymorphism reported for cobalt and zinc difluorides (30). Recently, palladium and silver difluorides have been shown to behave in a similar way forming cubic metastable phases (31). In all cases there is a decrease in volume for the structure change. 

This reaction between manganese difluoride and excess KrF2 in aHF at room temperature (after removal of Kr, F2, excess KrF2 and aHF in a dynamic vacuum), yields pure deep blue manganese tetrafluoride (z is the molar coefficient for the part of KrF2 that thermally decomposes to the elements). 

Up to 20 products with different numbers of fluorine atoms and double bonds have been isolated from the fluonnation of benzene with silver difluoride [d], manganese trifluoride [7], potassium tetrafluoroargentate [d], and potassium hexafluoronickelate [24] The composition of the products depends on the fluorinating agents and on the temperature (Table 1)... 

Table 1. Comparison of Fluorination of Benzene with Manganese Trifluoride [7], Potassium Hexafluoronickelate [24], Silver Difluoride [6], and Potassium Tetrafluorocobaltate [6]...

Oxygen (Gas), Carbon disulfide, Mercury, Anthracene, 4831 Oxygen (Liquid), Carbon, Iron(II) oxide, 4832 Oxygen difluoride, Hexafluoropropene, Oxygen, 4317 Potassium chlorate, Manganese dioxide, 4017 f Propionyl chloride, Diisopropyl ether, 1163 f Propylene oxide, Sodium hydroxide, 1225 Silver azide, 0023 Silver nitride, 0038 Sodium carbonate, 0552 Sodium peroxoborate, 0155 Tetrafluoroammonium tetrafluoroborate, 0133 Triallyl phosphate, 3184... 

The author next tried to stabilize the PGI2 structure by introducing second fluorine atom to the 7-position. However, it had been unknown to make such a difluorovinyl ether unit in the literature. We studied difluorination and Wittig reaction as key steps in the synthetic route of the target difluoro-PGl2 from the Corey lactone. After searching the difluorination reaction, it was found that fluorination with A/-fluorobenzenesulfonimide in the presence of potassium bis(trimethylsilyl) amide and manganese dibromide effectively provided the desired difluoride (Table 7) [106]. 

QNB (6581 -06-2) 3-quinuclidinyl benzilate. QUARTZ (14808-60-7) Dust and powder reacts with powerful oxidizers (fluorine, chlorine trifluoride, manganese trioxide, oxygen difluoride, etc.) may cause fire and explosions. Attacked by hydrofluoric acid and alkali solutions. 

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