AbstractThe synthesis of the binuclear complex [(NH3)] CrOhCr(NH3)4CH2CH2\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^{(+)} $\end{document}H36+, which has been obtained in the form of the well crystallised hexachloride is described. On adding alkali (titration in a rapid flow apparatus) the OH‐bridge (pK = 6,36) is first deprotonated and the terminal ammonium group (pK = 8,42) afterwards. Both deprotonation products are blue and highly unstable, hydrolysing rapidly to the hydroxo‐erythro ion and ethylenediamine.