Acid-base and counter ion dependent solid-state assembly of a ferrocene β-aminoalcohol and the corresponding ammonium salt

2-(Ferrocenylmethyl)amino-2-methylpropan-1-ol was synthesized and converted to the respective ammonium bromide ([1H]Br ≡ 2) and dihydrogenphosphate ([1H]H2PO4 ≡ 3). The solid-state structures of 1, 2 and the solvated salt 3 · 1/6Et2O (3a) have been determined by X-ray diffraction. The solid-state assemblies of 1 and 2 are dominated by infinite ladder-like arrays interconnected by hydrogen bonds whereas the solid-state structure of 3a is built up from linear hydrogen-bonded dihydrogenphosphate chains, which are interlinked via hydrogen bonds to the cations [1H]+ into a complicated three-dimensional network. Compound 1 and its interactions with Bu4NBr and Bu4NH2PO4 in solution were further studied by electrochemical methods and NMR titrations.