title: Electrostatic Potential Determined Magnetic Dynamics Observed in Two Mononuclear β-Diketone Dysprosium(III) Single-Molecule Magnets.
abstract: Two β-diketone mononuclear Dy(III) compounds, formulated as Dy(BTFA)3(H2O)2(1) and Dy(BTFA)3(bpy) (2) (BTFA = 3-benzoyl-1,1,1-trifluoroacetone, bpy = 2,2'-bipyridine), were prepared. Compound 1 can be identified to transform to 2 in the attendance of bpy coligand, when the local geometry symmetry of eight-coordinated Dy(III) ion changes from a dodecahedron (D2d) in 1 to a square antiprism (D4d) in 2. Fine-tuning structure aroused by auxiliary ligand has dramatical impact on magnetic properties of compounds 1 and 2. Magnetic investigations demonstrate that both 1 and 2 display dynamic magnetic relaxation of single-molecule magnets (SMMs) behavior with different effective barriers (ΔE/kB) of 93.09 K for 1 under zero direct-current (DC) field as well as 296.50 K for 1 and 151.01 K for 2 under 1200 Oe DC field, respectively. As noticed, compound 1 possesses higher effective barrier than 2, despite 1 exhibiting a lower geometrical symmetry of the Dy(III) ion. Ab initio studies reveal that the Kramers doublet ground state is predominantly axial with the gztensors of two compounds matching the Ising-limit factor of 20 anticipated for the pure MJ= ±15/2 state. Electrostatic analysis confirms the uniaxial anisotropy directions, highlighting that the proper electrostatic distribution of the coordination sphere around Ln(III) center is the critical factor to improve the magnetic anisotropy and determine the dynamic behaviors of SMMs.
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.
authors.forename: Pei-Pei
authors.initials: PP
authors.lastname: Cen
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.|College of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences , Baoji 721013, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, State Key Laboratory Cultivation Base of Natural Gas Conversion, Ningxia University , Yinchuan 750021, China.
authors.forename: Xiang-Yu
authors.identifier: http://orcid.org/0000-0001-8864-3411
authors.initials: XY
authors.lastname: Liu
authors.affiliation: College of Chemistry and Chemical Engineering, State Key Laboratory Cultivation Base of Natural Gas Conversion, Ningxia University , Yinchuan 750021, China.
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Song
authors.affiliation: Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University , Nanjing 210023, China.
authors.forename: Yi-Quan
authors.initials: YQ
authors.lastname: Zhang
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.
authors.forename: Gang
authors.initials: G
authors.lastname: Xie
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.
authors.forename: San-Ping
authors.initials: SP
authors.lastname: Chen