Tetraphenylarsonium(V) chloride hydrate is a common reactant and extractant that can be used to separate solid compounds from organic phases and aqueous solutions [1]. Traces of rhenium can be separated from larger amounts of Mo by shaking a chloroform solution of Tetraphenylarsonium(V) chloride hydrate with an aqueous solution at pH 8-9 containing ReO4−, thereby forming the CHCl3− soluble ion associate [(C6H5)4As+][ReO4−][2]. Tetraphenylarsonium(V) chloride hydrate is widely used as a model compound to study the thermodynamic properties over the temperature range from T=0 to T=340K[3].
References:
[1] Marić L, Široki M. Extraction of 4-(2-pyridylazo) resorcinol and 4-(2-thiazolylazo) resorcinol with chloroform and tetraphenylarsonium and phosphonium chlorides[J]. Analytica chimica acta, 1996, 318(3): 345-355.
[2] Willard H H, Smith G M. Tetraphenylarsonium chloride as an analytical reactant: Determination of rhenium[J]. Industrial & Engineering Chemistry Analytical Edition, 1939, 11(6): 305-306.
[3] Lebedev B V, Smirnova N N, Tsvetkova L Y, et al. Thermodynamic properties of tetraphenylphosphonium perchlorate and tetraphenylarsonium perchlorate fromT→ 0 toT= 340 K[J]. The Journal of Chemical Thermodynamics, 2001, 33(5): 485-498.