10,16-Dichloro-6,20-dioxa-3,23-diazatetracyclo[23.3.1.07,12.014,19]nonacosa-1(29),7,9,11,14(19),15,17,25,27-nonaene-4,22-dione methanol monosolvate

In the title compound, C25H22Cl2N2O4·CH3OH, the macrocyclic molecule adopts a slightly distorted C 2-symmetric conformation. The macrocyclic molecules are linked via N—H⋯O hydrogen bonds between the amide groups into chains extending along the [010] direction. The methanol molecules bridge these chains via N—H⋯O and O—H⋯O hydrogen bonds with the formation of a two-dimensional polymeric structure parallel to (001). The methanol molecule is disordered over two positions with the occupancy ratio of 9:1. The disorder of the solvent molecule is caused by weak intermolecular C—H⋯Cl hydrogen bonding.

In the title compound, C 25 H 22 Cl 2 N 2 O 4 ÁCH 3 OH, the macrocyclic molecule adopts a slightly distorted C 2 -symmetric conformation. The macrocyclic molecules are linked via N-HÁ Á ÁO hydrogen bonds between the amide groups into chains extending along the [010] direction. The methanol molecules bridge these chains via N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds with the formation of a two-dimensional polymeric structure parallel to (001). The methanol molecule is disordered over two positions with the occupancy ratio of 9:1. The disorder of the solvent molecule is caused by weak intermolecular C-HÁ Á ÁCl hydrogen bonding.   Table 1 Hydrogen-bond geometry (Å , ).  (Hayvali & Hayvali, 2005;Kleinpeter et al., 1997). They are studied for their role in bioprocesses, catalysis, material science, transport and separation (Jaiyu et al., 2007;Christensen et al., 1997;Alexander, 1995). In this paper, we report the crystal structure of a lactam ionophore (Fig.1). The macrocycle consists of three benzene rings, two of them substituted with chlorine atom in para position to O atom. The neighboring molecules are connected via hydrogen bonds between amide groups ( Table 1). The crystal contains methanol molecule disordered over two positions with partial occupancies of 0.90 and 0.10. The hydroxyl group of the solvent forms hydrogen bond to the oxygen atom of the amide group (Table 1). The methyl group of the methanol in second position is also weakly bound to the chlorine atoms of neighboring molecule. This weak interaction competes with the stronger hydrogen bond to amide group and causes the solvent disorder.

Experimental
All chemicals used were purchased from Fluka and used without further purification. The title compound was synthesized according to the method reported by Ertul et al. (2009). Single crystals were prepared by slow evaporation of methanol solution.

Refinement
Positions of disordered groups were found from electron density maps. The disordered fragments were then placed in appropriate positions, and all distances between neighbouring atoms were restrained to 1.406 (20) Å. Site occupancies were refined for the different parts with the common displacement parameters for corresponding atoms in various fragments. At the end of the refinement, site occupancies were fixed at the values 0.9 and 0.1 and hydrogen atoms were placed in calculated positions. All hydrogen atoms of the macrocyclic molecule were found from electron density difference maps. H atoms attached to C atoms were placed in calculated positions. N-H distances were initially restrained to 1.00 Å with σ=0.02 and then fixed. The isotropic displacement parameters of H atoms were calculated as 1.2U eq of the parent atom.

Figure 1
View of the asymmetric unit of the title compound with displacement ellipsoids shown at the 50% probability level. Cbound H atoms have been omitted for clarity.

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. 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 > σ(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. Positions of disordered groups were found from electron density maps. The disordered fragments were then placed in appropriate positions, and all distances between neighbouring atoms were fixed. Site occupancies were refined for the different parts with the same thermal parameters for same atoms in various fragments. At the end of the refinement, site occupancies were fixed at values 0.90 and 0.10 and hydrogen atoms were placed into calculated positions. All hydrogen atoms could be found from maps of difference electron density, but those, attached to carbon atoms, were placed into calculated positions. The distance between N and H atoms were restrained to 1.00 Å with σ=0.02. The isotropic temperature parameters of hydrogen atoms were calculated as 1.2*U eq of the parent atom.