Four coordination compounds {[Cd(L)_1/2(H₂O)₂]·2H₂O}_n (1), {[Ni₂(L)(bpyBr)₂(H₂O)₂]·H₂O}_n (2), {[Ni(H₂L)(bipy)(H₂O)]·H₂O}_n (3), and [Co(H₂L)(bipy)(H₂O)₂]_n (4) (H₄L = 5,5′-(pentane-1,4-diylbis(oxy))diisophthalic acid, bpyBr = 4,4′-dibromo-2,2′-bipyridyl, bipy = 4,4′-bipyridine) were synthesized and characterized. These four compounds exhibit a 3D open framework with channels, a 2D layer, a 3D supramolecular network constructed from coordination layers and a 3D supramolecular network constructed from coordination chains, respectively. The reaction temperature can influence the coordination modes of the organic multi-carboxylate ligands and the acidity of the compounds. AC impedance spectral studies suggest that the order of proton conductivity of compounds 1–4 is 3 > 4 > 1 > 2. The result reveals that the proton conductivities of low dimensional nonporous CPs 3 and 4 are higher than that of high dimensional porous CP 1. The structure–property studies reveal that the highest proton conductivity of 3 may be explained by its acidic hydrophilic groups and highest water uptake. The dimensionality and channels of the CPs can't influence proton conductivity directly. Meanwhile the amount and orientation of hydrophilic groups can decide the water absorption ability of the CPs, which is an important factor on proton conductivity. The protonation degree of hydrophilic groups, i.e. the acidity of the CPs is the first influencing factor. So, large amounts of hydrophilic groups with high protonation degrees should be considered firstly in the design and synthesis of CPs with good proton conducting performance.

中文翻译：

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四种具有不同酸度和吸水率的多孔和无孔配位聚合物的质子传导研究

四种配位化合物{[Cd（L）_1/2（H ₂ O）₂ ]·2H ₂ O} _n（1），{[Ni ₂（L）（bpyBr）₂（H ₂ O）₂ ]·H ₂ O} _n（2），{[Ni（H ₂ L）（bipy）（H ₂ O）]·H ₂ O} _n（3）和[Co（H ₂ L）（bipy）（H ₂ O）₂ ] _n（4）（高₄合成L = 5,5'-（戊烷-1,4-二基双（氧基））二间苯二甲酸，bpyBr = 4,4'-二溴-2,2'-联吡啶，bipy = 4,4'-联吡啶表征。这四种化合物显示具有通道的3D开放框架，2D层，由配位层构建的3D超分子网络和由配位链构建的3D超分子网络。反应温度可以影响有机多羧酸盐配体的配位方式和化合物的酸度。交流阻抗谱研究表明，化合物1-4的质子传导率顺序为3 > 4 > 1 > 2。结果表明，低维无孔CP的质子电导率图3和4比高维多孔CP 1的高。的结构-性质的研究表明，最高的质子传导性3可通过其酸性亲水基团和最高水吸收进行说明。CP的尺寸和通道不能直接影响质子的电导率。同时，亲水基团的数量和取向可以决定CP的吸水能力，这是影响质子电导率的重要因素。亲水基的质子化程度，即CP的酸度是第一个影响因素。因此，在具有良好质子传导性能的CP的设计和合成中，应首先考虑大量具有高质子化程度的亲水基团。