title: Fine-Tuning Ligand to Modulate the Magnetic Anisotropy in a Carboxylate-Bridged Dy2 Single-Molecule Magnet System.
abstract: A series of dinuclear Dy(III) compounds with the general formula [Dy2(μ2-anthc)4(anthc)2(L)2] (anthc(-) = 9-anthracenecarboxylate, L = 2,2'-bipyridyl (1), 1,10-phenanthroline (2), and 4,7-dimethyl-1,10-phenanthroline (3)) were synthesized and magnetically characterized. These compounds exhibit single-molecule magnet (SMM) behavior in the absence of the direct-current field, which is rarely observed for carboxylate-bridged dinuclear Dy2 system. With the first coordination sphere of Dy(III) centers being fixed, the energy barrier was modulated by sequentially modifying the terminal neutral L ligands in this Dy2 system. Theoretical calculations revealed that the symmetry of the charge distribution surrounding the Dy(III) centers in 1-3 is the decisive factor to determine the relaxation of the SMMs. The combination of the larger charge distribution along the magnetic axis and lower charge distribution in the equatorial plane (hard plane) formed by five coplanar coordination atoms including two N atoms provided by an L ligand led to a strong easy-axis ligand field in these compounds. This work presents a rational method to modulate the dynamic magnetic relaxation of the lanthanide SMMs through fine-tuning electrostatic potential of the atoms on the hard plane.
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang, Jiangxi 330022, P. R. China.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang, Jiangxi 330022, P. R. China.
authors.forename: Chang-Bao
authors.initials: CB
authors.lastname: Han
authors.affiliation: Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University , Nanjing 210023, P. R. China.
authors.forename: Yi-Quan
authors.initials: YQ
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang, Jiangxi 330022, P. R. China.
authors.forename: Qing-Yan
authors.initials: QY
authors.lastname: Liu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institution of Chemistry, Chinese Academy of Sciences, Center for Molecular Sciences , Beijing 100190, P. R. China.
authors.forename: Cai-Ming
authors.initials: CM
authors.lastname: Liu
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang, Jiangxi 330022, P. R. China.
authors.forename: Shun-Gao
authors.initials: SG
authors.lastname: Yin