Two mononuclear cobalt(II)complexes,with the formulas[Co(2,6-dfba)_(2)(bpp)_(2)(H_(2)O)_(2)]_(n)(1)and[Co(2,6-dfba)_(2)(bpe)_(2)(H_(2)O)_(2)]_(n)(2)(2,6-Hdfba=2,6-difluorobenzoic acid,bpp=1,3-bis(4-pyridyl)propane,bpe...Two mononuclear cobalt(II)complexes,with the formulas[Co(2,6-dfba)_(2)(bpp)_(2)(H_(2)O)_(2)]_(n)(1)and[Co(2,6-dfba)_(2)(bpe)_(2)(H_(2)O)_(2)]_(n)(2)(2,6-Hdfba=2,6-difluorobenzoic acid,bpp=1,3-bis(4-pyridyl)propane,bpe=1,2-bis(4-pyridyl)ethylene),have been synthesized by combining Co(II)ions with benzoate derivatives and two homogeneous N-donor ligands,respectively.Constrained by the analogous CoN_(2)O_(4)coordination spheres,the discretely hexa-coordinated Co(II)cores in both complexes display stretched octahedral geometries.The equatorial environments in both complexes are identical,whereas the axial sites are finely modulated by the different chemical natures of the terminal N-donor ligands.The combined analyses of the magnetic data,the high-frequency electron paramagnetic resonance(HF-EPR)and the ab initio calculations unveil large easy-plane magnetic anisotropies for both complexes(D=+53.19 and+65.67 cm^(-1)for 1 and 2,respectively),which function as field-induced single-ion magnets(SIMs)with effective barriers(U_(eff))of 45.34(1)and 57.97 K(2).This work demonstrates how fine-tuning the coordination microenvironment of metal ions results in a non-negligible manipulation of their magnetic anisotropy.展开更多
基金National Natural Science Foundation of China(No.21863009 and 21701046)Third Batch of Ningxia Youth Talents Supporting Program(TJGC2018038)+1 种基金National First-rate Discipline Construction Project of Ningxia(Chemical Engineering and Technology)(NXYLXK2017A04)MINECO(Spain)(Project CTQ2016-75671-P and Excellence Unit“Maria de Maeztu”MDM-2015-0538)。
文摘Two mononuclear cobalt(II)complexes,with the formulas[Co(2,6-dfba)_(2)(bpp)_(2)(H_(2)O)_(2)]_(n)(1)and[Co(2,6-dfba)_(2)(bpe)_(2)(H_(2)O)_(2)]_(n)(2)(2,6-Hdfba=2,6-difluorobenzoic acid,bpp=1,3-bis(4-pyridyl)propane,bpe=1,2-bis(4-pyridyl)ethylene),have been synthesized by combining Co(II)ions with benzoate derivatives and two homogeneous N-donor ligands,respectively.Constrained by the analogous CoN_(2)O_(4)coordination spheres,the discretely hexa-coordinated Co(II)cores in both complexes display stretched octahedral geometries.The equatorial environments in both complexes are identical,whereas the axial sites are finely modulated by the different chemical natures of the terminal N-donor ligands.The combined analyses of the magnetic data,the high-frequency electron paramagnetic resonance(HF-EPR)and the ab initio calculations unveil large easy-plane magnetic anisotropies for both complexes(D=+53.19 and+65.67 cm^(-1)for 1 and 2,respectively),which function as field-induced single-ion magnets(SIMs)with effective barriers(U_(eff))of 45.34(1)and 57.97 K(2).This work demonstrates how fine-tuning the coordination microenvironment of metal ions results in a non-negligible manipulation of their magnetic anisotropy.
