The displacement of ammonia in [Rh(NH3)5H]2+ by aliphatic amines is described. The compounds, trans-[Rh en2(NH3)H][ClO4]2 and trans-[Rh pn2(NH3)H][ClO4]2(en = ethylenediamine, pn = 1,2-diaminopropane) have been isolated; in aqueous solution these are equilibrium with the corresponding cis-isomer. The displacement of the trans-ammonia, by water, is discussed.
