Crystal structure of 2-hydroxy-N-(2-hydroxyethyl)-N-{2-hydroxy-3-[(E)-N-hydroxyethanimidoyl]-5-methylbenzyl}ethanaminium acetate monohydrate

The structure of the title hydrated molecular salt, C14H23N2O4 +·C2H3O2 −·H2O, was determined as part of a wider study on the use of the molecule as a polydentate ligand in the synthesis of MnIII clusters with magnetic properties. The cation features intramolecular O—H⋯N and N—H⋯O hydrogen-bond interactions. The crystal structure features a range of intermolecular hydrogen-bonding interactions, principally O—H⋯O interactions between all three species in the asymmetric unit. An R 2 4(8) graph-set hydrogen-bonding motif between the anion and water molecules serves as a unit which links to the cation via the diethanolamine group. Each O atom of the acetate anion accepts two hydrogen bonds.


S1. Chemical context
The structure of the title hydrated salt was determined as part of a wider study on the synthesis of polymetallic compounds with potentially interesting magnetic properties. The phenolic oximes are a ligand family which have had enormous success in the construction of Mn cluster compounds that behave as single molecule magnets (Milios et al., 2007;Inglis et al., 2012). These ligand types tend to form systems based on the [Mn 3 O(L) 3 ] + (L = salicylaldoxime) building block (Vlahopoulou et al., 2009;Stamatatos et al., 2007;Milios et al., 2006). An additional functional group was introduced onto the aromatic framework of the ligand in an attempt to disrupt the formation of clusters based on this motif and to see if higher nuclearity compounds based on phenolic oximes could be isolated. A diethanolamine functional group was the obvious choice given that the this has an excellent track record of making magnetically interesting Mn clusters in its own right (Tasiopoulos & Perlepes, 2008). For examples of the use of the H 4 L in the synthesis of magnetic materials, see Frost et al. (2014) and Sanz et al. (2014aSanz et al. ( , 2014b.

S2. Structural commentary
A check of the molecular geometry with Mogul showed all geometric parameters to be unexceptional. A mean plane fitted through atoms O1, O2, N1 and C1 to C10 (i.e. all ring atoms plus the oxime and hydroxyl groups) has an rms deviation of 0.029 Å.

S3. Supramolecular features
The crystal structure features extensive hydrogen bonding, principally O-H···O interactions involving all species in the asymmetric unit. Intramolecular interactions within the cation are, perhaps, less important but serve to support the overall structure by locking the cation conformation. The N2-H2A···O1 interaction in particular is probably quite weak. The R 2 4 (8) graph set motif between the anion and water molecules serves as an important unit which links to the cation via the hydroxyethane groups to propagate the three-dimensional structure. Hydrogen bonding information is summarised in Table 2.

S5. Refinement
Crystal data, data collection and structure refinement details are summarised in Table 1. All H atoms were located in a difference Fourier map and refined freely.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. All H atoms were located in a difference Fourier map and refined freely.