Premium
Tuning the Magnetization Dynamic Properties of Nd⋅⋅⋅Fe and Nd⋅⋅⋅Co Single‐Molecular Magnets by Introducing 3 d–4 f Magnetic Interactions
Author(s) -
Wei RongMin,
Liu Ting,
Li Jing,
Zhang Xiuling,
Chen Yuting,
Zhang YiQuan
Publication year - 2019
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.201900139
Subject(s) - diamagnetism , crystallography , chemistry , magnetization , paramagnetism , raman spectroscopy , relaxation (psychology) , ion , magnet , magnetic anisotropy , ab initio , materials science , magnetic field , condensed matter physics , physics , organic chemistry , psychology , social psychology , quantum mechanics , optics
By using paramagnetic [Fe(CN) 6 ] 3− anions in place of diamagnetic [Co(CN) 6 ] 3− anions, two field‐induced mononuclear single‐molecular magnets, [Nd(18‐crown‐6)(H 2 O) 4 ][Co(CN) 6 ] ⋅ 2 H 2 O ( 1 ) and [Nd(18‐crown‐6)(H 2 O) 4 ][Fe(CN) 6 ] ⋅ 2 H 2 O ( 2 ), have been synthesized and characterized. Single‐crystal X‐ray diffraction analysis revealed that compounds 1 and 2 were ionic complexes. The Nd III ions were located inside the cavities of the 18‐crown‐6 ligands and were each bound by four water molecules on either side of the crown ether. Magnetic investigations showed that these compounds were both field‐induced single‐molecular magnets. By comparing the slow relaxation behaviors of compounds 1 and 2 , we found significant differences between the direct and Raman processes for these two complexes, with a stronger direct process in compound 2 at low temperatures. Complete active space self‐consistent field (CASSCF) calculations were also performed on two [Nd(18‐crown‐6)(H 2 O) 4 ] 3+ fragments of compounds 1 and 2 . Ab initio calculations showed that the magnetic anisotropies of the Nd III centers in complexes 1 and 2 were similar to each other, which indicated that the difference in relaxation behavior was not owing to the magnetic anisotropy of Nd III . Our analysis showed that the magnetic interaction between the Nd III ion and the low‐spin Fe III ion in complex 2 played an important role in enhancing the direct process and suppressing the Raman process of the single‐molecular magnet.