Dissolution equilibria of arsenic pentafluoride in anhydrous hydrogen fluoride

Dissolution equilibria of arsenic pentafluoride in anhydrous hydrogen fluoride have been quantitatively examined by measuring the scattering intensity of the Raman spectra of the corresponding species in the solution at ambient conditions. For the superacid formation reaction, 2HF+AsF5⇄H2F++AsF6−, K1 (=[H2F+][AsF6−]/[HF]2[AsF5]) has been determined to be ∼2×10−5 mol−1 kg, and dinucleation reaction of the anion, AsF6−+AsF5⇄As2F11−, K2 (=[As2F11−]/[AsF6−][AsF5]) to be ∼8×10−1 mol−1 kg, respectively.