一维链状3-碘苯甲酸铽配合物的合成、晶体结构和性质表征

溶液法合成了配合物{Tb(3-IBA)₃(H₂O)₂]·0.5(4，4′-bipy)}_n(3-IBA=3-碘苯甲酸根；4，4′-bipy=4，4′-联吡啶)，并通过X-射线衍射单晶结构分析、红外光谱、紫外光谱、荧光光谱以及热重分析对配合物进行了结构和性质表征。配合物晶体属三斜晶系，P1空间群。该配合物具有一维链状结构。Tb³⁺离子与8个O原子配位，其中6个O原子来自5个3-碘苯甲酸根，2个O原子来自水分子。相邻Tb³⁺离子通过2个双齿桥联的3-碘苯甲酸根联结成一维链状结构。未配位的4,4′-联吡啶分子与配位水分子之间形成氢键，并将相邻的一维链联结起来形成二维网状结构。沿a轴的分子堆积形成一维孔道，是由于相邻一维链的苯环之间部分重叠而形成的。在紫外光照射下，配合物发出很强的绿色荧光。配合物的荧光光谱中，4个峰位于490、544、583和619 nm，分别对应于Tb³⁺离子的⁵D₄→⁷F₆、⁵D₄→⁷F₅、⁵D₄→⁷F₄和⁵D₄→⁷F₃跃迁。

Synthesis, Crystal Structure and Characterization of 1D Chain-like Terbium 3-iodobenzoate Complex

The complex of Tb(3-IBA)3(H2O)2]·0.5(4,4'-bipy)}n(3-IBA=3-iodobenzoate; 4,4'-bipy=4,4'-bipyridine) was prepared by solvent method and further characterized by X-ray single crystal structural analysis, IR spectrum,UV spectrum, fluorescence spectrum, and thermogravimetric analysis. The complex crystallizes in triclinic crystal system and P1 space group with the cell dimensions: a=0.957 9(2) nm, b =1.020 3(2) nm, c=1.667 5 (3) nm, α=95.4660(10)°, β=105.0010(10)°, γ=106.9940 (10)°. The complex has 1D chain-like structure. Tb3+ ion is eightcoordinated by six oxygen atoms from five 3-IBA ligands and two oxygen atoms from water molecules. The adjacent Tb3+ ions are linked by two bidentate-bridging 3-IBA ligands forming 1D chain-like structure. The hydrogen bonds are formed between the free 4,4'-bipy molecules and the coordination water molecules, which connect the 1D chains into 2D network structure. Viewed along a-axis, there appear 1D channels caused by the partial overlapping between the benzene rings of the neighboring chains. The complex exhibits strong green fluorescence under ultraviolet light and the fluorescence spectrum has four main peaks at 490, 544, 583 and 619nm, corresponding to 5D4→7F6、54→7F5、5D4→7F4and5D4→7F3 transition emissions of the Tb3+ ion, respectively.