摘要
Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
在水热和溶剂热条件下,用半刚性多齿化合物5-(1-羧基乙氧基)间苯二甲酸(H3CIA)分别与1,4-二(4H-1,2,4-三唑-4-基)苯(1,4-dtb)和1,4-二(1H-咪唑-1-基)苯(1,4-dib)两种氮杂环配体协同配位Co^(2+)离子,成功构筑了2种新型钴基配合物{[CO_(2)(CIA)(OH)(1,4-dtb)]·2H2O}n(HU23)和{[CO_(2)(CIA)(OH)(1,4-dib)]·3.5H_(2)O·DMF}n(HU24)。单晶X射线衍射分析表明,2个配合物中CIA^(3-)阴离子均呈κ^(7)配位模式,其所含的5个羧基氧原子和1个醚基氧原子与6个Co^(2+)离子配位,形成了四核的[Co4(μ3-OH)2]^(6+)金属氧簇单元。金属氧簇单元通过CIA^(3-)桥联组装成具有3,6-连接特征的kgd型二维层状结构。在HU23和HU24中,1,4-dtb和1,4-dib进一步将二维层连接形成三维的柱层式框架。值得注意的是,尽管1,4-dtb和1,4-dib具有相似的分子构型,但二者配位差异导致HU23和HU24的三维框架结构出现拓扑分化:三维框架可分别简化为3,10-连接网络(点符号:(4^(10).6^(33).8^(2))(4^(3)_(2))和3,8-连接的tfz-d型网络(点符号:(4^(3))_(2))(4^(6).6^(18).8^(4)))。这种结构差异证实了配体对金属有机框架拓扑结构的精确调控作用。紫外可见吸收光谱显示HU23和HU24对紫外和可见光有较强的吸收能力,经Kubelka-Munk法得到其带宽分别为2.15和2.08 eV,具有典型半导体材料特征。变温磁化率测试(2~300 K)表明,2个配合物均呈现明显的反铁磁行为,其有效磁矩随温度降低而显著减小。
出处
《无机化学学报》
北大核心
2026年第1期45-54,共10页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21761036)
广西大学生创新训练项目(No.202410605029)资助。
