Poly[(μ5-2-methyl-3,5-dinitrobenzoato)sodium]

In the crystal of the title coordination polymer, [Na(C8H5N2O6)]n, the Na(I) ion is linked to five nearby anions. Their bonding modes are three monodentate carboxylate O atoms, one O,O′-bidentate carboxylate group and one O,O′-bidentate nitro group. This results in an irregular NaO7 coordination geometry for the metal ion. This connectivity leads to a layered network propagating in (100).

In the crystal of the title coordination polymer, [Na(C 8 H 5 N 2 O 6 )] n , the Na(I) ion is linked to five nearby anions. Their bonding modes are three monodentate carboxylate O atoms, one O,O 0 -bidentate carboxylate group and one O,O 0 -bidentate nitro group. This results in an irregular NaO 7 coordination geometry for the metal ion. This connectivity leads to a layered network propagating in (100).

Related literature
For the structure of a trimethyl-tin complex with the orthotoluate ligand, see: Danish et al. (2010).

Comment
The structure of compound (1) is composed of molecular sheets in which Na(I) ions are bridged by ligand carboxylate and nitro-group O atoms. The carboxylate O1 atom acts as bidentate and chelates Na1 and Na1(IV) ions, the O2 atom is bonded to Na1(II) and Na1(V) ions and to the Na1 ion at a longer distance of 2.780 (2) Å. The O1, O2, Na and Na (II) ions form a distorted plane [r.m.s. 0.0261 (2) Å], the O1 atom chelates the Na (IV) ion below this plane, the O2 atom -the Na (V) ion above, giving rise to a molecular column. However, when distances between atoms from a nitro-group of an adjacent ligand to the Na ion are accounted for, the columns form molecular sheets. The coordination geometry of the Na1 ion is represented by a strongly distorted eight-faced polyhedron with an equatorial plane formed by carboxylate O1 and O2(II), nitro O21(VI) and The sheets are held together via weak interactions of the van der Waals type since the closest approach between two atoms from adjacent sheets is 3.54 (4) Å.
Experimental 0.0119 mol of 3,5-dinitro-ortho toluic acid was suspended in 15 ml of distilled water contained in a round-bottom flask.
Then, 0.0119 mol of an aqueous solution of sodium bicarbonate was added drop-wise with stirring. The mixture was refluxed for 3 h and concentrated to half of its volume, then left at room temperature. Crude crystals appeared within a week. Yellow needles of (I) crystals were obtained by recrystallization from a water/ethanol 3:1 mixture at room temperature.