Topological modulation of metal–thiadiazole dicarboxylate coordination polymers through auxiliary ligand alteration
作者:Zhen-Xin Zhao、Yun-Wu Li、Sui-Jun Liu、Li-Fu Wang、Ze Chang、Jian Xu、Ying-Hui Zhang
DOI:10.1039/c5ce00649j
日期:——
Five new CoII/ZnII coordination polymers (CPs), namely [Co(tdzdc)(4,4â²-bipy)(H2O)]n (1), [Co(tdzdc)(bpp)(H2O)]·3H2O}n (2), [Zn2(tdzdc)2(4,4â²-bipy)(H2O)2]·3H2O}n (3), [Zn2(tdzdc)2(obpy)(H2O)2]n (4) and [Zn(tdzdc)(tmb)]n (5), have been synthesized based on the primary ligand 1,2,5-thiadiazole-3,4-dicarboxylic acid (H2tdzdc) together with four selected N/O-donor auxiliary ligands, i.e., 4,4â²-bipy: 4,4â²-bipyridine, bpp: 1,3-bi(pyridin-4-yl)propane, obpy: [4,4â²-bipyridine]-N,Nâ²-dioxide, and tmb: 1,4-bis((1H-1,2,4-triazol-1-yl)methyl)benzene. Single-crystal structural analyses unveil different topologies and interpenetration degrees of 1â5, associated with four different kinds of coordination modes of H2tdzdc that depend on the auxiliary ligands used. CPs 1â4 are all constructed by extending the one-dimensional metalâligand chain through the respective auxiliary ligands. Among them, the linear rigid auxiliary ligands (i.e., bipy and obpy) generate two-dimensional planes of 1, 3 and 4, which exhibit different interpenetration degrees of 0, 2 and 3, respectively, while the flexible bpp auxiliary ligand forms a three-dimensional net of 2. In contrast, CP 5 has a basic structural unit comprising dinuclear metal clusters that facilitate the formation of a 3-fold interpenetrated two-dimensional net extended through the tmb auxiliary ligand. Furthermore, magnetic investigations of the two CoII-based CPs reveal that despite being mediated by synâanti bridging of the carboxylate, both 1 and 2 display antiferromagnetic and canted antiferromagnetic behaviors, respectively.
五种新的 CoII/ZnII 协同聚合物 (CPs),即 [Co(tdzdc)(4,4′-bipy)(H2O)]n (1)、[Co(tdzdc)(bpp)(H2O)]·3H2O}n (2)、[Zn2(tdzdc)2(4,4′-bipy)(H2O)2]·3H2O}n (3)、[Zn2(tdzdc)2(obpy)(H2O)2]n (4) 和 [Zn(tdzdc)(tmb)]n (5),是基于主配体 1,2,5-噻二唑-3,4-二羧酸 (H2tdzdc) 合成的,同时选择了四种 N/O 供体辅助配体,即 4,4′-bipy:4,4′-联吡啶,bpp:1,3-双(pyridin-4-yl)丙烷,obpy:[4,4′-联吡啶]-N,N′-二氧化物,以及 tmb:1,4-双((1H-1,2,4-三唑-1-基)甲基)苯。单晶结构分析揭示了 1-5 的不同拓扑结构和交错程度,这与 H2tdzdc 的四种不同配位模式有关,具体取决于使用的辅助配体。CPs 1-4 均通过各自的辅助配体扩展了一维金属-配体链。其中,线性刚性辅助配体(即 bipy 和 obpy)生成了 1、3 和 4 的二维平面,其交错程度分别为 0、2 和 3,而灵活的 bpp 辅助配体形成了 2 的三维网络。相比之下,CP 5 的基本结构单元由二核金属簇组成,促进了通过 tmb 辅助配体形成三重交错的二维网络。此外,对两个基于 CoII 的 CP 的磁性研究表明,尽管由羧酸的顺-反桥接介导,1 和 2 分别表现出反铁磁和倾斜反铁磁特性。