4-Carb-oxy-2-methyl-1H-imidazol-3-ium-5-carboxyl-ate monohydrate

The crystal structure of 5-carboxy-2-(hydroxymethyl)-1H-imidazol-3-ium-4-carboxylate, C6H8N2O6

C6H8N2O6, monoclinic, P21/c (no. 14), a = 7.4709(4) Å, b = 14.2051(9) Å, c = 7.3198(4) Å, β $\beta $  = 97.096(4)°, V = 770.86(8) Å3, Z = 4, R gt (F) = 0.0346, wR ref (F 2) = 0.0946, T = 200 K.

Structural characterization of two tetra-chlorido-zincate salts of 4-carb-oxy-1H-imidazol-3-ium: a salt hydrate and a co-crystal salt hydrate

Imidazole-containing compounds exhibit a myriad of pharmacological activities. Two tetra-chlorido-zincate salts of 4-carb-oxy-1H-imidazol-3-ium, ImHCO2H+, are reported. Bis(4-carb-oxy-1H-imidazol-3-ium) tetra-chlorido-zincate monohydrate, (C4H5N2O2)2[ZnCl4]·H2O, (I), crystallizes as a monohydrate salt, while bis-(4-carb-oxy-1H-imidazol-3-ium) tetra-chlorido-zincate bis-(1H-imidazol-3-ium-4-carboxyl-ato) monohydrate, (C4H5N2O2)2[ZnCl4]·2C4H4N2O2·H2O, (II), is a co-crystal salt with six residues: two ImHCO2H+ cations, two formula units of the zwitterionic 1H-imidazol-3-ium-4-carboxyl-ate, ImHCO2, one tetra-chlorido-zincate anion and one water mol-ecule disordered over two sites in a 0.60 (4):0.40 (4) ratio. The geometric parameters of the ImHCO2H+ and the ImHCO2 moieties are the same within the standard uncertainties of the measurements. Both compounds exhibit extensive hydrogen bonding, including involvement of the tetra-chlorido-zincate anion, resulting in inter-connected chains of anions joined by water mol-ecules.

5-Carb-oxy-2-isopropyl-1H-imidazol-3-ium-4-carboxyl-ate monohydrate

In the title compound, C(8)H(10)N(2)O(4)·H(2)O, the imidazole N atom is protonated and one of the carboxyl-ate groups is deprotoned, forming a zwitterion. An intra-molecular O-H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds. In addition, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into two-dimensional networks parallel to (10[Formula: see text]).