Investigations of magnetic and thermal expansion properties of two cobalt(II) metal-organic frameworks constructed by mixed bipyridyl-tetracarboxylate strategy

Huang，Xing Cai1; Kong，Jiao Jiao1; Yang，Shun Yi2; Zhu，Junlun2; Yang，Jiong3; Shao，Dong2

2025-01-15

10.1016/j.molstruc.2024.139676

Journal of Molecular Structure   影响因子和分区

0022-2860

We report the syntheses, crystal structures, adsorption behavior, thermal expansion behavior, and magnetic properties of two cobalt(II) metal-organic frameworks (MOFs), {[Co(btca)(bpe)(HO)]·bpe} (1) and {Co(btca)(bpe)(DMF)} (2, Hbtca = 1,2,4,5-benzenetetracarboxylic acid; bpe = 1,2-di(4-pyridyl)ethane), constructed using mixed bipyridyl and tetracarboxylate ligands. Single-crystal X-ray diffraction (SC-XRD) indicates that the change of synthetic solvents leads to a significant tuning of structural dimensionality from 2D to 3D framework. Temperature-dependent SC-XRD reveals anisotropically negative and positive thermal expansion of the compounds identified along different crystallographic axes within the frameworks over a 120–400 K temperature range. N adsorption measurements indicate a nonporous and ultramicroporous framework for 1 and 2, respectively. Magnetic measurements indicate an easy-plane magnetic anisotropy of the Co ions in the MOFs, with experimental D values of 63.1 and 87.1 cm. The ac susceptibility measurements of 1 and 2 show field-induced slow magnetic relaxation below 6 K through different relaxation dynamics. This work not only provides two new cobalt(II) SIM-MOFs, but also presents an effective bipyridyl-tetracarboxylate strategy for designing and building framework materials with interesting magnetic and mechanical properties.

Cobalt(Ii) Magnetic property Magnetic relaxation Negative thermal expansion Single-ion magnet

英语

其他

CHEMISTRY

2-s2.0-85201627490

Scopus

1.School of Chemistry and Environmental Engineering,Yancheng Teachers University,Yancheng,224007,China
2.Hubei Key Laboratory of Processing and Application of Catalytic Materials,College of Chemistry and Chemical Engineering,Huanggang Normal University,Huanggang,438000,China
3.Department of Chemistry,Southern University of Science and Technology (SUSTech),Shenzhen,518055,China

Huang，Xing Cai,Kong，Jiao Jiao,Yang，Shun Yi,et al. Investigations of magnetic and thermal expansion properties of two cobalt(II) metal-organic frameworks constructed by mixed bipyridyl-tetracarboxylate strategy[J]. Journal of Molecular Structure,2025,1320.

Huang，Xing Cai,Kong，Jiao Jiao,Yang，Shun Yi,Zhu，Junlun,Yang，Jiong,&Shao，Dong.(2025).Investigations of magnetic and thermal expansion properties of two cobalt(II) metal-organic frameworks constructed by mixed bipyridyl-tetracarboxylate strategy.Journal of Molecular Structure,1320.

Huang，Xing Cai,et al."Investigations of magnetic and thermal expansion properties of two cobalt(II) metal-organic frameworks constructed by mixed bipyridyl-tetracarboxylate strategy".Journal of Molecular Structure 1320(2025).