Crystal structure of bis[1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole-κN3]silver(I) tetrafluoridoborate methanol monosolvate

Abstract

1-(2-Hydroxyethyl)-2-methyl-5-nitro-1H-imidazole (metronidazole, MET) is a medication that is used to treat infections by a variety of anaerobic organisms, but there are relatively few reports of the structures of metal compounds that exhibit coordination of metronidazole. We have demonstrated that MET reacts with AgBF4 to give [Ag(MET)2]BF4·CH3OH, in which the AgI cation is coordinated by two MET ligands with a trans arrangement. The structure of [Ag(MET)2]BF4 exhibits some interesting differences from its nitrate counterpart, [Ag(MET)2]NO3 [Fun et al. (2008). Acta Cryst. E64, m668]. For instance, although the two MET ligands of both [Ag(MET)2]BF4 and [Ag(MET)2]NO3 are almost coplanar, the former compound has an anti-like geometry with a molecular inversion center, but the latter has a syn-like arrangement. In the crystal, the BF4− anion is linked by an O—H...F hydrogen bond to the methanol solvent molecule, which is, in turn, linked to the cation by an O—H...O hydrogen bond; the components of the structure are linked by O—H...O hydrogen bonds, forming chains along [001]. One of the MET ligands and the BF4− anion are disordered over two sets of sites with ratios of refined occupancies 0.501 (17):0.499 (17) and 0.539 (19):0.461 (19), respectively.

Keywords

• crystal structure
• silver
• metronidazole
• Flagyl
• tetrafluoridoborate
• hydrogen bonding