Tetraalkylammonium nitratoborates [R4N][B(NO3)4], R=CH3, C2H5 were produced by the reaction of liquid nitrogen tetraoxide with the corresponding tetrachloridoborates, their density was determined, and the x-ray diffraction patterns and IR spectra were taken. Both salts are hydrolytically stable and insoluble in water.
Both complexes are dimorphic; the temperature of reversible phase transformation is 51° for [(CH3)4N][B(NO3)4] and 64° for [(C2H5)4N][B(NO3)4].
The temperature interval was established and the products of thermal decomposition of the nitratoborates obtained were determined. The decomposition of [(CH3)4N][B(NO3)4] begins at 75°, [(C2H5)4N] ·[B(NO3)4] at 130°. The decomposition products represent a mixture of [R4N]NO3 and B2O3; the gas phase contains nitrogen dioxide and oxygen.