Investigating the crystal structures of alkali and alkaline-earth metal salts of 2,5-(dianilino)terephthalic acid

International audienceFrom the reactions between 2,5-(dianilino)terephthalic acid and Li2CO3 or MgIJOH)2 in water, three new layered compounds were prepared. The corresponding structures were determined by single crystal X-ray diffraction studies. Depending on the experimental conditions, two polymorphs can be obtained when using Li2CO3 as base namely [(LiIJOH2)3)2IJC20H14N2O4)]·2H2O (Ia) and [(LiIJOH2)4)2IJC20H14N2O4)] (Ib). Compound Ia (form α) crystallizes in the P1¯ space group with lattice parameters a = 7.4372(6) Å, b = 8.2866(5) Å, c = 10.6200IJ13) Å, α = 98.674IJ7)°, β = 107.377IJ14)°, and γ = 90.655IJ6)°, whereas compound Ib (form β) adopts the P21/c space group with cell parameters a = 11.955(2) Å, b = 6.2885(4) Å, c = 16.030(2) Å, and β = 91.726IJ12)°. The neutralization reaction with MgIJOH)2 leads to the formation of [MgIJOH2)6IJC20H14N2O4)]·2.8H2O (II), which crystallizes in the P1¯ space group with lattice parameters a = 13.6558IJ19) Å, b = 15.903(3) Å, c = 16.6894IJ10) Å, α = 94.295IJ11)°, β = 113.23IJ1)°, and γ = 110.377IJ11)°. All these structures can be systematically described by the stacking of alternating bi-layers as previously reported with the sodiated counterpart. One layer consists of 2,5-(dianilino)terephthalate dianions (C20H14N2O42−) while the other is composed of the corresponding cations (Li+ or Mg2+) coordinated by water molecules.The distance between the two layers depends on the nature of the cation and its coordination as well as the conformation of the organic anion. Such original 2-D host lattices appear quite interesting as anion-inserting electrode materials for promoting the emerging field of p-type rechargeable organic batteries