Two open-framework zinc phosphates [C3N2H12][Zn(HPO4)2] (1) and [C6N4H22]0.5[Zn(HPO4)2] (2) were synthesized via hydrothermal reaction and characterized by powder X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Both compounds have a similar crystal structure and macroscopic morphology. However, the difference in equilibrium cations, in which the propylene diamine is for 1 and the triethylenetetramine is for 2, results in a significant distinction in the dense hydrogen grid. The diprotonated propylene diamine molecule in 1 is more favorable for forming a hydrogen-bond network in three dimensions than in 2, in which the twisted triethylenetetramine forms a hydrogen bond grid with the inorganic framework only in two dimensions owing to its large steric effect. This distinction further leads to a disparity in the proton conductivity of both compounds. The proton conductivity of 1 can reach 1.00 × 10-3 S cm-1 under ambient conditions (303 K and 75% RH) and then increase to 1.11 × 10-2 S cm-1 at 333 K and 99% RH, which is the highest value among the open-framework metal phosphate proton conductors operated in the same conduction. In contrast, the proton conductivity of 2 is four orders of magnitude smaller than 1 at 303 K and 75% RH and two orders smaller than 1 at 333 K and 99% RH.

中文翻译：

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具有相似晶体结构和不同氢键网络的两种一维开放框架金属磷酸盐的质子传导行为。

通过水热反应合成了两种开放骨架磷酸锌 [C3N2H12][Zn(HPO4)2] (1) 和 [C6N4H22]0.5[Zn(HPO4)2] (2)，并通过粉末 X 射线衍射、热重分析对其进行了表征和扫描电子显微镜。两种化合物具有相似的晶体结构和宏观形态。然而，平衡阳离子的差异，其中丙二胺为1，三乙烯四胺为2，导致致密氢网格明显不同。1中的双质子化丙二胺分子比2中更利于形成三维氢键网络，其中扭曲的三乙烯四胺由于其大的空间效应仅在二维中与无机骨架形成氢键网格。这种区别进一步导致两种化合物的质子传导率不同。1 的质子电导率在环境条件下（303 K 和 75% RH）可达 1.00 × 10-3 S cm-1，然后在 333 K 和 99% RH 下增加到 1.11 × 10-2 S cm-1，即在同一传导中运行的开放式框架金属磷酸盐质子导体中的最高值。相比之下，2 的质子传导率在 303 K 和 75% RH 时比 1 小四个数量级，在 333 K 和 99% RH 时比 1 小两个数量级。