Theppitak Chatphorn, Kielar Filip, Dungkaew Winya, Sukwattanasinitt Mongkol, Kangkaew Laongdao, Sahasithiwat Somboon, Zenno Hikaru, Hayami Shinya, Chainok Kittipong
Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-McMa), Faculty of Science and Technology, Thammasat University Pathum Thani 12121 Thailand
Department of Chemistry, Faculty of Science and Technology, Thammasat University Pathum Thani 12121 Thailand.
RSC Adv. 2021 Jul 15;11(40):24709-24721. doi: 10.1039/d1ra03106f. eCollection 2021 Jul 13.
The influence of synthetic conditions on the solid-state structural formation of lanthanide(iii) complexes based on a hydrazide ligand have been investigated and reported. Depending on the solvents and reaction temperatures, the reactions of hydrated Ln(NO) with a benzohydrazide (bzz) ligand afforded three classes of lanthanide(iii) coordination complexes . Ln(bzz)(NO) (1Ln; Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5)), [Ln(bzz)(ben)(HO)]·HO (2Ln; Ln = Pr (6), Nd (7), Sm (8), Eu (9), Gd (10), Tb (11), Dy (12), Er (13)), and [Ln(ben)] (3Ln; Ln = Eu (14), Gd (15), Tb (16), Dy (17), Er (18), Tm (19), Yb (20), Lu (21)). Complexes 1-5 in series 1Ln were isolated by slow evaporation of their isopropanol solutions at ambient temperature, and the complexes display similar discrete structures bearing distinct intermolecular N-H⋯O hydrogen bonds to generate a three-dimensional (3D) supramolecular architecture. Complexes 6-13 in series 2Ln were obtained under hydrothermal conditions at 110 °C where the generated benzoate (ben) ligands participated in the formation of one-dimensional (1D) coordination polymers (CPs) with the bzz ligands. At a temperature of 145 °C the hydrothermal conditions result in the formation of the thermodynamically more stable products of 14-21 in series 3Ln, in which the bzz ligand underwent complete hydrolysis to create the ben ligand. These coordination assemblies feature 1D zigzag chains that are formed by unusual low coordination numbers of the six- and seven-fold coordinated Ln centers bridged by the ben ligands in - and -coordination modes. Notably, the chain structures of 2Ln can be transformed into the zigzag tape-like structures of 3Ln upon heating the crystalline samples to 400 °C in air. In the solid state at room temperature, the Eu- (2, 9, 14) and Tb- (4, 11, 16) containing complexes emit red and green light, respectively. The luminescence investigations show that the Eu- (9, 14) and Tb-(11, 16) based CPs could be used as fluorescent probes for acetone and Co ions an energy competition mechanism. Meanwhile, the Gd- (10, 15) and Dy- (12, 17) based CPs show typical antiferromagnetic interactions.
研究并报道了合成条件对基于酰肼配体的镧系(III)配合物固态结构形成的影响。根据溶剂和反应温度，水合Ln(NO)与苯甲酰肼(bzz)配体反应得到三类镧系(III)配位配合物。Ln(bzz)(NO) (1Ln；Ln = Sm (1)、Eu (2)、Gd (3)、Tb (4)、Dy (5))，[Ln(bzz)(苯甲酸根)(H₂O)]·H₂O (2Ln；Ln = Pr (6)、Nd (7)、Sm (8)、Eu (9)、Gd (10)、Tb (11)、Dy (12)、Er (13))，以及[Ln(苯甲酸根)] (3Ln；Ln = Eu (14)、Gd (15)、Tb (16)、Dy (17)、Er (18)、Tm (19)、Yb (20)、Lu (21))。系列1Ln中的配合物1 - 5通过在室温下缓慢蒸发其异丙醇溶液分离得到，这些配合物呈现出类似的离散结构，带有不同的分子间N - H⋯O氢键，以生成三维(3D)超分子结构。系列2Ln中的配合物6 - 13是在110℃水热条件下得到的，其中生成的苯甲酸根(苯甲酸根)配体与bzz配体参与形成一维(1D)配位聚合物(CPs)。在145℃的温度下，水热条件导致系列3Ln中热力学上更稳定的产物14 - 21的形成，其中bzz配体发生完全水解生成苯甲酸根配体。这些配位组装体具有1D之字形链，由苯甲酸根配体以 - 和 - 配位模式桥连的六配位和七配位Ln中心的不寻常低配位数形成。值得注意的是，将晶体样品在空气中加热到400℃时，2Ln的链结构可转变为3Ln的之字形带状结构。在室温固态下，含Eu - (2, 9, 14)和Tb - (4, 11, 16)的配合物分别发出红光和绿光。发光研究表明，基于Eu - (9, 14)和Tb - (11, 16)的CPs可作为丙酮和Co离子的荧光探针，存在能量竞争机制。同时，基于Gd - (10, 15)和Dy - (12, 17)的CPs表现出典型的反铁磁相互作用。
