The coordination chemistry of benzhydrazide with lanthanide(iii) ions: hydrothermal in situ ligand formation, structures, magnetic and photoluminescence sensing properties

Chatphorn Theppitak; Filip Kielar; Winya Dungkaew; Mongkol Sukwattanasinitt; Laongdao Kangkaew; Somboon Sahasithiwat; Hikaru Zenno; Shinya Hayami; Kittipong Chainok

doi:10.1039/d1ra03106f

The coordination chemistry of benzhydrazide with lanthanide(iii) ions: hydrothermal in situ ligand formation, structures, magnetic and photoluminescence sensing properties

RSC Adv. 2021 Jul 15;11(40):24709-24721. doi: 10.1039/d1ra03106f. eCollection 2021 Jul 13.

Authors

Chatphorn Theppitak^{1

2}, Filip Kielar³, Winya Dungkaew⁴, Mongkol Sukwattanasinitt⁵, Laongdao Kangkaew⁶, Somboon Sahasithiwat⁶, Hikaru Zenno⁷, Shinya Hayami⁷, Kittipong Chainok¹

Affiliations

¹ Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-McMa), Faculty of Science and Technology, Thammasat University Pathum Thani 12121 Thailand kc@tu.ac.th.
² Department of Chemistry, Faculty of Science and Technology, Thammasat University Pathum Thani 12121 Thailand.
³ Department of Chemistry, Faculty of Science, Naresuan University Phitsanulok 65000 Thailand.
⁴ Department of Chemistry, Faculty of Science, Mahasarakham University Maha Sarakham 44150 Thailand.
⁵ Department of Chemistry, Faculty of Science, Chulalongkorn University Bangkok 10330 Thailand.
⁶ National Metal and Materials Technology Center (MTEC), The National Science and Technology Development Agency Pathum Thani 12121 Thailand.
⁷ Department of Chemistry, Graduate School of Science and Technology and Institute of Pulsed Power Science, Ku-mamoto University 2-39-1 Kurokami, Chuoku Kumamoto 860-8555 Japan.

Abstract

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(NO₃)₃ with a benzohydrazide (bzz) ligand afforded three classes of lanthanide(iii) coordination complexes viz. [Ln(bzz)(NO₃)](NO₃)₂ (1Ln; Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5)), [Ln(bzz)(ben)₃(H₂O)]·H₂O (2Ln; Ln = Pr (6), Nd (7), Sm (8), Eu (9), Gd (10), Tb (11), Dy (12), Er (13)), and [Ln₃(ben)₃] (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 in situ 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 in situ 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 Ln³⁺ centers bridged by the ben ligands in μ ₂- and μ ₃-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 Co²⁺ ions via an energy competition mechanism. Meanwhile, the Gd- (10, 15) and Dy- (12, 17) based CPs show typical antiferromagnetic interactions.