Structure of 1,3-bis(carboxymethyl)imidazole

Brønsted Acidic Ionic Liquids and Their Zwitterions: Synthesis, Characterization and pKa Determination

“…[19] More interesting is the presence of a strong hydrogenbonding network in both compounds; Figure 2 shows the interaction of the chloride ion in 6 and 8 with proximate hydrogen atoms, all being closer than 3 . Such hydrogen bonding is well known from other imidazolium chloride structures, [17,19,25] but it is especially pronounced in 6 and 8, in which there are eight contacts close (< 3 ) to the chloride stemming from six different cations. The strongest interactions arise from the OH protons, with OÀH···Cl distances and angles of 2.18 and 167.08 (6) and 2.21 and 169.18 (8), respectively.…”

“…[16] The solid-state structure of VI (n = 1) determined by single-crystal X-ray diffraction reveals the presence of CH 2 COO À and CH 2 COOH units. [17] These groups are connected by strong intermolecular O···HÀO hydrogen bonding with O···O = 2.463 , possibly contributing to the high melting (decomposition) point of 290 8C. Furthermore, addition of CO 2 or CS 2 to 1,3-dialkylimidazolium-2-ylidenes affords 2-imidazolium zwitterions (VII), [18] and the condensation reaction between 1-methylimidazole and dimethyl carbonate leads to similar compounds (VIII).…”

1-Carboxymethyl-3-methyl-1H-imidazol-3-ium chloride 2-(3-methyl-1H-imidazol-3-ium-1-yl)acetate monohydrate: a crystal stabilized by imidazolium zwitterions

“…IR D-type bands of (I) in the 1300-400 cm À1 region were assigned to the stretching vibrations of the protons in the strong hydrogen bonds (Hadži, 1965). This type of band was also observed for the zwitterionic 1,3-bis(carboxymethyl)imidazole (Barczyń ski et al, 2008;Kratochvíl et al, 1988).…”

Glycylglycine-derived 1,3-disubstituted imidazole in nonenzymic browning reactions

“…The simplest representative of these imidazole derivatives, 3-(carboxymethyl)-l-imidazoliumethanoate [ 1,3-bis(carboxymethyl)-imidazole], was first isolated as a product of nonenzymatic browning reactions of glycine with glyoxal and formaldehyde (Kratochvil et al, 1988; Vel%ek et al, 1989). Later on, some other l,&disubstituted imidazoles, derived from a-dicarbonyls and monocarbonyls other than glyoxal and formaldehyde as well as from amino acids other than glycine, were identified (Velilek et al, 1989; Davidek, 1990).…”

“…matic browning reactions of glycine with glyoxal and formaldehyde (Kratochvil et al, 1988;Vel%ek et al, 1989). Later on, some other l,&disubstituted imidazoles, derived from a-dicarbonyls and monocarbonyls other than glyoxal and formaldehyde as well as from amino acids other than glycine, were identified (Velilek et al, 1989;Davidek, 1990).…”