Crystal structure of a (carboxymethyl)triethylazanium bromide–2-(triethylazaniumyl)acetate (1/1) hydrogen-bonded dimer

The title compound, C8H18NO2+·Br−·C8H17NO2, crystallizes as the bromide salt of a 50:50 mixture of (triethylazaniumyl)carboxylic acid and the zwitterionic (triethylazaniumyl)carboxylate. The two organic entities are linked by a half-occupied bridging carboxylic acid hydrogen atom that is hydrogen-bonded to the carboxylate group of the second molecule. The tetralkylammonium group adopts a nearly perfect tetrahedral shape around the nitrogen atom with bond lengths that agree with known values. The carboxylic acid/carboxylate group is oriented anti to one of the ethyl groups on the ammonium group, and the carbonyl oxygen atom is engaged in intramolecular C—H...O hydrogen bonds.