Perrhenate tetrabutylammonium

Additionally, the tetrabutylammonium- and tetraphenylarsoniumperrhenate have been spectroscopically studied. Exactly as seen in the case of the pertechnetates and permanganates, the vs bands are sharp and well defined. The perrhenates of different tetrammine- and hexammine-cations (75, 76) and rare earth cations (121 a) have also been reported. 

A quantity of tetrabutylammonium hydrogen sulfate 28.7 g (Aldrich), that has been recrystallized from acetone, is added to 300 mL of warm methanol in a 500-mL beaker. To this is added a solution of aqueous perrhenic acid (28.0 g, 80 to 85%, titrated 75.7%) (Alfa) with stirring. The total volume is then reduced by boiling to 125 mL, and the solution is then cooled slowly to 0 °C yielding white needles of [CH3(CH2)3]4NRe04. The supernatant liquid is further condensed to 50 mL and the resulting needles are combined with the initial crystalline product and twice recrystallized from methanol to give 30.8 g (74% yield) of product (mp 236-237 °C). 

Sodium perrhenate (2.0 g, 7.3 mmol) is dissolved in demineralized water (100 mL) in a 250-mL conical flask. The solution is stirred and heated to 60°C then added to a warm (60°C) solution of tetrabutylammonium chloride (2.6 g, 9.3 mmol) in demineralized water (100 mL) in a 250-mL conical flask. The solution is left to stir for 30 min at room temperature. The white solid which forms is collected on a No. 3 sintered-glass filter tube, by filtration, and washed with distilled water (4 x 20 mL) and diethyl ether (4 x 30 mL) and dried in vacuo for 5 h at 56°C (boiling acetone) (yield 2.86 g, 79%). 

The Beckmann rearrangement of cyclohexanone oximes produces caprolactams in high yield if the reaction is carried out in the presence of tetrabutylammonium perrhenate <93CL489>, and enaminolactams are obtained by the photolytic rearrangement of a,jS-unsaturated ketone oximes <88JCS(Pl)32l>. The treatment of acylated or sulfonylated oximes with trimethylsilyl iodide or... 

Tetrabutylammonium perrhenate is a white solid that is stable in air. It is soluble in... 

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