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Neutron diffraction studies of the 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid and 4,4'-bipyridine.

The 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid (BTA) and 4,4'-bipyridine (BPY) have been studied using neutron diffraction at 215 and 20 K, respectively. BTA and BPY crystallize in a 1:1 ratio with 1.8 molecules of water, viz. 4,4'-bipyridinium 2,5-dicarboxybenzene-1,4-dicarboxylate 1.8-hydrate, C(10)H(12)N(2)(2+).C(10)H(4)O(8)(2-).1.8H(2)O, (I), in the space group P-1, with both BTA and BPY lying on inversion centres. BTA and BPY crystallize in a 2:1 ratio, viz. 4,4'-bipyridinium bis(2,4,5-tricarboxybenzoate), C(10)H(12)N(2)(2+).2C(10)H(5)O(8)(-), (II), in the space group Cc. The crystal structure of the 1:1 cocrystal contains one short N-H...O hydrogen bond [N...O = 2.6047 (19) A] and one intramolecular O-H...O hydrogen bond [O...O = 2.423 (3) A]. The crystal structure of the 2:1 cocrystal contains two N-H...O hydrogen bonds [N...O = 2.639 (3) and 2.674 (2) A], and two intramolecular [O...O = 2.404 (3) and 2.420 (3) A] and four strong intermolecular O-H...O hydrogen bonds [O...O = 2.613 (3), 2.718 (3), 2.628 (3) and 2.739 (3) A].[1]

References

  1. Neutron diffraction studies of the 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid and 4,4'-bipyridine. Cowan, J.A., Howard, J.A., Mason, S.A., McIntyre, G.J., Lo, S.M., Mak, T., Chui, S.S., Cai, J., Cha, J.A., Williams, I.D. Acta crystallographica. Section C, Crystal structure communications. (2006) [Pubmed]
 
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