catena-Poly[(μ-anilido)(μ-1,2-dimethoxyethane-κ3-O,O′:O)sodium]

In the title compound, [Na(C6H5NH)(C4H10O2)], the Na+ cation is coordinated by the N atoms of two anilide anions, two O atoms of a chelating 1,2-dimethoxyethane (dme) ligand and one O atom of an adjacent dme ligand. The coordination polyhedron around Na+ corresponds to a distorted square pyramid with the N atoms of the anilide groups and the O atoms of the chelating dme unit at the base and a third O atom at the apical position. The anilide anions act as μ-bridging ligands and the 1,2-dimethoxyethane molecules display a μ2-κ3-O,O′ coordination mode. As a result of this connectivity, a polymeric chain structure parallel to [100] is formed, consisting of Na2O2 and Na2N2 four-membered rings. It should be noted that the remaining H atom of the anilide NH group is not involved in hydrogen bonding.

In the title compound, [Na(C 6 H 5 NH)(C 4 H 10 O 2 )], the Na + cation is coordinated by the N atoms of two anilide anions, two O atoms of a chelating 1,2-dimethoxyethane (dme) ligand and one O atom of an adjacent dme ligand. The coordination polyhedron around Na + corresponds to a distorted square pyramid with the N atoms of the anilide groups and the O atoms of the chelating dme unit at the base and a third O atom at the apical position. The anilide anions act as -bridging ligands and the 1,2-dimethoxyethane molecules display a 2 -3 -O,O 0 coordination mode. As a result of this connectivity, a polymeric chain structure parallel to [100] is formed, consisting of Na 2 O 2 and Na 2 N 2 four-membered rings. It should be noted that the remaining H atom of the anilide NH group is not involved in hydrogen bonding.

Experimental
Crystal data [Na(C 6 et al., 1995). Like in the case of the pmdeta derivative, the Na + cations are linked by the PhNH groups to give planar Na 2 N 2 rings with the phenyl groups in a trans arragement. The Na 2 N 2 ring exhibits a rhombus shape with both the N-Na-N angle (93.22 (4)°) and the Na-N-Na angle (86.78 (4)°) close to 90°. A similar shaped Na 2 N 2 ring has been observed in the pmdeta derivative (N-Na-N: 92.6°; Na-N-Na: 87.4°). The phenyl rings display a nearly perpedicular orientation with respect to the Na 2 N 2 plane (82.16 (5) et al., 2007). Due to the µ-bridging mode of the dme molecules four membered Na 2 O 2 rings possessing crystallographic 1 symmetry are formed. The Na 2 N 2 and Na 2 O 2 rings are linked by corner sharing to give an infinite chain parallel to [100].
The tilt angle between the Na 2 N 2 and Na 2 O 2 rings is 72.33 (4)°. Using a polyhedral model, the chain structure can be described by edge-sharing NaO 3 N 2 square pyramids (Fig. 2). Interestingly, the H atom of the anilide NH group is not involved in hydrogen bonding.
Experimental 0.7 ml (7.7 mmol) of aniline were added dropwise to a suspension of 0.29 g (7.5 mmol) of sodium amide in 10 ml of 1,2dimethoxyethane. After one hour of stirring, the pale yellow reaction solution was reduced to 8 ml and afterwards layered with 20 ml of n-hexane. Colourless crystals of [Na(PhNH)(dme)] are formed at the phase boundary after one week. The product was filtered off and washed with n-pentane. Yield: 1.11 g (72%).

Refinement
The H atom bonded to N was located from a difference Fourier map and was refined freely. Hydrogen atoms attached to the phenyl group and hydrogen atoms of the dme ligand were positioned geometrically and refined using a riding model with U(H) = 1.20 U eq (C).

Computing details
Data

Figure 1
The coordination around the Na + cation in the structure of the title compound. The asymmetric unit is marked by filled bonds. Anisotropic displacement parameters are drawn at the 50% probability level. [Symmetry codes: i: 1 -x, -y, 1 -z; ii: 2 -x, -y,  Part of the chain structure extending parallel to [100].

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.