Crystal structure of 1-[2-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-1-yl]propan-2-ol

The molecular and crystal structure of the title imidazole derivative is reported. The structure is stabilized by an extensive O—H⋯N, C—H⋯O/Cl and C—H⋯π(ring) hydrogen-bonding network.


Chemical context
Imidazole derivatives are important components of numerous natural products and are especially noted for their numerous pharmacological applications, particularly as anti-tumour agents (Bahnous et al., 2013;Belwal & Joshi, 2012). In addition, they also display anti-bacterial fungicidal and anti-parasitic properties (Sridharan et al., 2014;Mohammadi et al., 2012;Sharma et al., 2009). We have recently developed fast and efficient multi-component reactions, catalysed by the ionic liquid morphilinium hydrogen sulfate, to prepare imidazole derivatives in a single-step process (Marzouk et al., 2016). The title compound is the result of just such a synthetic process and we report its crystal structure here.

Figure 3
An overlay (Macrae et al., 2008) of the two molecules.
alternating type 1 and type 2 molecules along the c axis, Fig. 6. An interesting feature of the packing of these molecules is the formation of significant voids in the crystal structure with a volume amounting to 2039 Å 3 across the unit cell. This large void is unexpected as no solvent appeared and the final difference map was reasonably flat (see _refine_special_details in the CIF). The molecules stack in an orderly fashion along each of the three principal crystallographic axes and the voids are clearly visible in views of the overall packing along these directions, see for example Fig. 7.

Synthesis and crystallization
The compound was prepared by a literature procedure (Marzouk et al., 2016). Irregular colourless block-like crystals were grown from ethanol solution at room temperature. Rows of type 1 and 2 molecules along c linked by C-HÁ Á Á hydrogen bonds.

Figure 7
The overall packing of the two molecules of (I), viewed along the a axis. O-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds form zigzag C(7) chains of type 1 and 2 molecules along b.

Figure 5
C(12) chains of type 2 molecules along a formed by C-HÁ Á ÁCl hydrogen bonds.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The hydrogen atoms on O112 and O212 were located in a difference Fourier map and their coordinates refined with U iso = 1.5 U eq (O). All other H atoms were refined using a riding model with d(C-H) = 0.95 Å , U iso = 1.2U eq (C) for aromatic, 1.00 Å for methine and 0.99 Å for CH 2 H atoms, all with U iso = 1.2U eq (C) and 0.98 Å , U iso = 1.5U eq (C) for CH 3 H atoms. Seven reflections with F o >>> F c , were omitted from the final refinement cycles.    (2014); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015) and TITAN2000 (Hunter & Simpson, 1999); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015), enCIFer (Allen et al., 2004), PLATON (Spek, 2009), publCIF (Westrip 2010) and WinGX (Farrugia 2012). 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. Refinement. 7 reflections with Fo >>> Fc were omitted from the final refinement cycles. The large void volume is unexpected as no solvent appeared or has been SQUEEZED out.