Ethane‐1,2‐di­ammonium bis(4‐nitro­benzoate) dihydrate

The structure of the title compound, C2H10N22+·2C7H4NO4−·2H2O, comprises interdigitated two-dimensional hydrogen-bonded networks derived from a repeat unit that contains the bis­ammonium, two benzoates and two water mol­ecules.

The structure of the title compound, C 2 H 10 N 2 2+ Á2C 7 H 4 NO 4 À Á-2H 2 O, comprises interdigitated two-dimensional hydrogenbonded networks derived from a repeat unit that contains the bisammonium, two benzoates and two water molecules.
The solid-state packing of (I) involves two symmetryindependent two-dimensional hydrogen-bonded networks individually derived from the repeat unit represented in Fig. 2 by molecules A±C, O1w and O2w. Both networks, comprising molecules A±C, O1w and O2w, and D±F, O3w and O4w, respectively, are essentially identical, the symmetry between the groupings being broken by the interdigitation of the 4-NBA molecules. Crosslinking through the associations of the water molecules to adjacent carboxylate O atoms creates the second dimension in the network. Hydrogen-bonding interactions are listed in Table 1.
All H atoms on the amines were initially located in difference syntheses but were then included in the re®nement (along with all other H atoms) at calculated positions as riding models, with NÐH set to 0.89 A Ê and CÐH set to 0.97 (CH 2 ) and 0.93 A Ê (Ar±H), while the isotropic displacement parameters were set equal to 1.25U eq of the carrier atom. All water H atoms were located in difference syntheses and both positional and isotropic displacement parameters were re®ned.

Figure 1
The asymmetric unit of the title compound, showing the atom-numbering scheme and 50% probability displacement ellipsoids.

Figure 2
One instance of the hydrogen-bonded unit that extends to form the twodimensional networks of (I). [Symmetry code: (i) 1 À x, 1 À y, 1 À z.]
The solid-state packing of (I) involves two symmetrically unique two-dimensional hydrogen-bonded networks individually derived from the repeat unit represented in Fig. 2 by molecules A-C, O1w and O2w. Both networks, comprising of molecules A-C, O1w and O2w, and D-F, O3w andO 4w, respectively, are essentially identical with the symmetry between the groupings being broken by the interdigitation of the 4-NBA molecules. Crosslinking through the associations of the water molecules to adjacent carboxylate O atoms creates the second dimension in the network.
Hydrogen-bonding interactions are listed in Table 1.

S3. Refinement
All H atoms on the amines were initially located in difference syntheses but were then included in the refinement (along with all other H atoms) at calculated positions as riding models, with N-H set to 0.89 Å and C-H set to 0.97 (CH 2 ) and 0.93 Å (Ar-H), while the isotropic displacement parameters were set equal to 1.25U eq of the preceeding normal atom.
All water H atoms were located on difference syntheses and both positional and isotropic displacement parameters were refined.

Figure 1
The molecular configuration and atom-numbering scheme for the title compound, showing 50% probability ellipsoids.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x