title: A triple-bridged azido-Cu(II) chain compound fine-tuned by mixed carboxylate/ethanol linkers displays slow-relaxation and ferromagnetic order: synthesis, crystal structure, magnetic properties and DFT calculations.
abstract: A new azido-Cu(II) compound, [Cu(4-fba)(N3)(C2H5OH)] (4-fba = 4-fluorobenzoic acid) (1), has been synthesized and characterized. The X-ray crystal structure analysis demonstrates that only one crystallographically independent Cu(II) ion in the asymmetric unit of 1 exhibits a stretched octahedral geometry in which two azido N atoms and two carboxylic O atoms locate in the equatorial square, while two ethanol O atoms occupy the apical positions, forming a 1D Cu(II) chain with an alternating triple-bridge of EO-azido, syn,syn-carboxylate, and μ2-ethanol. The title compound consists of ferromagnetically interacting ferromagnetic chains, which exhibit ferromagnetic order (T(c) = 7.0 K). The strong ferromagnetic coupling between adjacent Cu(II) ions within each chain is due to the countercomplementarity of the super-exchange pathways, whereas the ferromagnetic interchain interactions--responsible for the long-range magnetic ordering--are most likely due to the presence of coordinated ethanol molecules establishing hydrogen bonds with neighboring chains. DFT calculations have been performed on compound 1 to offer a qualitative theoretical explanation of the magnetic behavior.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China. sanpingchen@126.com.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Liu
authors.forename: Sanping
authors.initials: S
authors.lastname: Chen
authors.forename: Thais
authors.initials: T
authors.lastname: Grancha
authors.forename: Emilio
authors.initials: E
authors.lastname: Pardo
authors.forename: Hongshan
authors.initials: H
authors.lastname: Ke
authors.forename: Bing
authors.initials: B
authors.lastname: Yin
authors.forename: Qing
authors.initials: Q
authors.lastname: Wei
authors.forename: Gang
authors.initials: G
authors.lastname: Xie
authors.forename: Shengli
authors.initials: S
authors.lastname: Gao