Soleimannejad Janet, Aghabozorg Hossein, Motyeian Elham, Ghadermazi Mohammad, Attar Gharamaleki Jafar, Adams Harry
Acta Crystallogr Sect E Struct Rep Online. 2007 Dec 12;64(Pt 1):o231-2. doi: 10.1107/S1600536807065270.
The title proton-transfer compound, C(3)H(12)N(2) (2+)·2C(7)H(4)NO(4) (-)·2C(7)H(5)NO(4)·8H(2)O or (pnH(2))(pydcH)(2).2(pydcH(2))·8H(2)O, was obtained by the reaction of pyridine-2,6-dicarboxylic acid (pydcH(2)) and propane-1,3-diamine (pn) in aqueous solution. Both neutral and monoanionic forms of the diacid are observed in the crystal structure. The negative charge of two monoanions is balanced by the dicationic propane-1,3-diaminium species. In addition, considerable π-π stacking inter-actions between the aromatic rings of the (pydcH)(-) and (pydcH(2)) fragments [with centroid-centroid distances of 3.5108 (11)-3.5949 (11) Å] are observed. The most important feature of this crystal structure is the presence of a large number of O-H⋯O, O-H⋯N, N-H⋯O, N-H⋯N, C-H⋯O and C-H⋯N hydrogen bonds, with D⋯A ranging from 2.445 (2) to 3.485 (3) Å. These inter-actions as well as ion pairing and π-π stacking connect the various fragments into a supra-molecular structure.
质子转移化合物C(3)H(12)N(2) (2+)·2C(7)H(4)NO(4) (-)·2C(7)H(5)NO(4)·8H(2)O或(pnH(2))(pydcH)(2).2(pydcH(2))·8H(2)O是通过吡啶 - 2,6 - 二羧酸（pydcH(2)）与丙烷 - 1,3 - 二胺（pn）在水溶液中反应得到的。在晶体结构中观察到二酸的中性和单阴离子形式。两个单阴离子的负电荷由二价阳离子丙烷 - 1,3 - 二铵物种平衡。此外，观察到(pydcH)(-)和(pydcH(2))片段的芳环之间存在相当多的π - π堆积相互作用[质心 - 质心距离为3.5108 (11) - 3.5949 (11) Å]。该晶体结构最重要的特征是存在大量的O - H⋯O、O - H⋯N、N - H⋯O、N - H⋯N、C - H⋯O和C - H⋯N氢键，D⋯A范围为2.445 (2)至3.485 (3) Å。这些相互作用以及离子对和π - π堆积将各种片段连接成超分子结构。
