1-(Methyl-α-d-glucopyranosid-6-yl)-3-vinylimidazolium iodide dimethylformamide monosolvate

The title compound is a glucopyranoside compound containing a cationic vinylimidazolium moiety. The glucopyranoside ring shows a distinctive chair conformation.


Structure description
[MeGluVIm]I is part of a sub-category of ionic liquids, called carbohydrate-based ionic liquids (CHILs; Jopp, 2020). These molecules are defined as ionic organic compounds in which either the cation or the anion consists of an intact carbohydrate moiety. Our group has recently discovered a straightforward synthetic strategy for CHILs, in which methyl--d-glucopyranoside is transformed into methyl--d-6-iodoglucopyranoside in the first step (Skaanderup et al., 2002) and then in the second step quarternized with an Nsubstituted imidazole of choice to achieve a carbohydrate-based ionic liquid (Schnegas & Jopp, 2021). The title compound [MeGluVIm]I contains a vinylimidazolium ring bound to atom C6 of the glucopyranoside. Fig. 1 shows the asymmetric unit, including one molecule of dimethylformamide, which was used as the reaction solvent. The title compound crystallizes in a monoclinic unit cell. The crystal structure contains three classical hydrogen bonds and additional C-HÁ Á ÁO/I interactions (Table 1). One hydrogen bond is formed between O3-H3A of the glucopyranoside and O7 of DMF data reports with an HÁ Á ÁH length of 2.09 (4) Å . Two additional hydrogen bonds exists between the [MeGluVIm] cation and the iodide anion, which are O4-H4AÁ Á ÁI1 with 2.71 (5) Å and O5-H5AÁ Á ÁI1 with 2.75 (5) Å . Fig. 2 gives an alternative view of the cation, indicating the distinctive chair conformation of the glucopyranoside as well as the overall stereochemistry of the compound. The configurations of the stereogenic centres in the chosen cation are S (C1), R (C2), S (C3), S (C4) and R (C5).

Figure 1
Molecular structure of the title compound. Displacement ellipsoids correspond to 50% probability.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The crystal studied was refined as a two-component inversion twin.

Funding information
We acknowledge financial support by the Deutsche Forschungsgemeinschaft and the University of Rostock within the funding programme Open Access Publishing.

data-1
IUCrData ( Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

data-2
IUCrData (2022). 7, x220265 Refinement. All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.98 (methyl groups), 0.99Å (methylene groups), 1.00Å (methine groups) or 0.95 Å (aryl CH) and with U iso (H) = 1.5 times U eq (C) (methyl groups) or with U iso (H) = 1.2 times U eq (C) (methylene groups, aryl CH, methine groups). Torsion angles of all methyl groups were allowed to refine. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. Refined as a two-component inversion twin.