I have a really old sample of sodium tetraphenylborate. It should be white, but it is red. Does anyone know what was formed and how it influences precipitation of cations in water?
Stable aqueous NaTPB solutions are a transparent, flesh-toned color. During the initial stages of decomposition (or instability),the solution turns a golden color. As the quantity of TPB- that has decomposed increases, the solution turns dark red, then brown, and eventually black.
In the presence of oxygen "phenol and phenylboronic acid are produced as well as benzene, biphenyl, and other benzene ring derivatives".