Six two- and three-component ammonium carboxylate salt structures with a ladder-type hydrogen-bonding motif, three incorporating neutral carboxylic acid molecules

Six ammonium carboxylate salts are synthesized and reported, namely 2-propyl-ammonium benzoate, C₃H₁₀N⁺· C₇H₅O₂ ^-, (I), benzyl-ammonium (R)-2-phenyl-propion-ate, C₆H₁₀N⁺·C ₉H₉O₂ ^-, (II), (RS)-1-phenyl-ethyl- ammonium naphthalene-1-car-box-yl-ate, C₈H₁₂N ⁺·C₁₁H₇O₂ ^-, (III), benzyl-ammonium-benzoate-benzoic acid (1/1/1), C₆H ₁₀N⁺·C₇H₅O₂ ^-·C₇H₆O₂, (IV), cyclo-propyl-ammonium-benzoate-benzoic acid (1/1/1), C3H8N⁺· C7H5O2 ^-·C₇H₆O₂, (V), and cyclo-propyl-ammonium-ea-cis-cyclo-hexane-1,4-dicarboxyl-ate-ee-trans-cyclo- hexane-1,4-dicarb-oxy-lic acid (2/1/1), 2C₃H₈N ⁺·C₈H₁₀O₄ ^2-·C₈H₁₂O₄, (VI). Salts (I)-(III) all have a 1:1 ratio of cation to anion and feature three N ⁺ - H⋯O^- hydrogen bonds which form one-dimensional hydrogen-bonded ladders. Salts (I) and (II) have type II ladders,consisting of repeating R₄³(10) rings, while (III) has type III ladders, in this case consisting of alternating R₄²(8) and R ₄⁴(12) rings. Salts (IV) and (V) have a 1:1:1 ratio of cation to anion to benzoic acid. They have type III ladders formed by three N⁺ - H⋯O^- hydrogen bonds, while the benzoic acid mol-ecules are pendant to the ladders and hydrogen bond to them via O -H⋯O^- hydrogen bonds. Salt (VI) has a 2:1:1 ratio of cation to anion to acid and does not feature any hydrogen-bonded ladders; instead, the ionized and un-ionized components form a three-dimensional network of hydrogen-bonded rings. The two-component 1:1 salts are formed from a 1:1 ratio of amine to acid. To create the three-component salts (IV)-(VI), the ratio of amine to acid was reduced so as to deprotonate only half of the acid mol-ecules, and then to observe how the un-ionized acid mol-ecules are incorporated into the ladder motif. For (IV) and (V), the ratio of amine to acid was reduced to 1:2, while for (VI) the ratio of amine to acid required to deprotonate only half the diacid mol-ecules was 1:1.