Hydrogen-bonded one-dimensional networks in 1:1 complexes of N,N'-bis(2-pyridyl)aryldiamines with anilic acid

The 1:1 complexes N,N'-bis(2-pyridyl)benzene-1,4-diamine-anilic acid (2,5-dihydroxy-1,4-benzoquinone) (1/1), C(16)H(14)N(4).C(6)H(4)O(4), (I), and N,N'-bis(2-pyridyl)biphenyl-4,4'-diamine-anilic acid (1/1), C(22)H(18)N(4).C(6)H(4)O(4), (II), have been prepared and their solid-state structures investigated. The component molecules of these complexes are connected via conventional N-H.O and O-H.N hydrogen bonds, leading to the formation of an infinite one-dimensional network generated by the cyclic motif R(2)(2)(9). The anilic acid molecules in both crystal structures lie around inversion centres and the observed bond lengths are typical for the neutral molecule. Nevertheless, the pyridine C-N-C angles [120.9 (2) and 120.13 (17) degrees for complexes (I) and (II), respectively] point to a partial H-atom transfer from anilic aicd to the bispyridylamine, and hence to H-atom disorder in the OHN bridge. The bispyridylamine molecules of (I) and (II) also lie around inversion centres and exhibit disorder of their central phenyl rings over two positions.