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Tuning Magnetic Anisotropy in a Class of Co(II) Bis(hexafluoroacetylacetonate) Complexes
Author(s) -
Huang XingCai,
Li JiaXin,
Chen YongZhi,
Wang WenYan,
Xu Rui,
Tao JinXia,
Shao Dong,
Zhang YiQuan
Publication year - 2020
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201901625
Subject(s) - magnetic anisotropy , acetonitrile , chemistry , anisotropy , crystallography , octahedral molecular geometry , octahedron , ion , magnet , dimethylformamide , magnetic field , magnetization , crystal structure , physics , solvent , organic chemistry , quantum mechanics
Tuning the magnetic anisotropy of metal ions remains highly interesting in the design of improved single‐molecule magnets (SMMs). We herein report synthetic, structural, magnetic, and computational studies of four mononuclear Co II complexes, namely [Co(hfac) 2 (MeCN) 2 ] ( 1 ), [Co(hfac) 2 (Spy) 2 ] ( 2 ), [Co(hfac) 2 (MBIm) 2 ] ( 3 ), and [Co(hfac) 2 (DMF) 2 ] ( 4 ) (MeCN=acetonitrile, hfac=hexafluoroacetylacetone, Spy=4‐styrylpyridine, MbIm=5,6‐dimethylbenzimidazole, DMF=N,N‐dimethylformamide), with distorted octahedral geometry constructed from hexafluoroacetylacetone (hfac) and various axial ligands. By a building block approach, complexes 2 – 4 were synthesized by recrystallization of the starting material of 1 from various ligands containing solution. Magnetic and theoretical studies reveal that 1 – 4 possess large positive D values and relative small E parameters, indicating easy‐plane magnetic anisotropy with significant rhombic anisotropy in 1 – 4 . Dynamic alternative current (ac) magnetic susceptibility measurements indicate that these complexes exhibit slow magnetic relaxation under external fields, suggesting field‐induced single‐ion magnets (SIMs) of 1 – 4 . These results provide a promising platform to achieve fine tuning of magnetic anisotropy through varying the axial ligands based on Co(II) bis(hexafluoroacetylacetonate) complexes.