Strongest Ferromagnetic Coupling in Designed Gadolinium(III)–Nitroxide Coordination Compounds

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• 作者：Takuya Kanetomo ; Toru Yoshitake ; Takayuki Ishida
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：August 15, 2016
• 年：2016
• 卷：55
• 期：16
• 页码：8140-8146
• 全文大小：430K
• 年卷期：0
• ISSN：1520-510X

文摘

Three novel gadolinium(III)–radical complexes [Gd^III(hfac)₃(H₂O)(L)] [Gd-L; L = tert-butyl phenyl nitroxide (phNO) and its derivatives (tert-butyl 3-tolyl nitroxide and tert-butyl 4-tert-butylphenyl nitroxide)] were synthesized, and all compounds showed ferromagnetic coupling, obeying the empirical relation: out-of-plane coordination of the Gd ion from the radical π system favors ferromagnetic coupling. In particular, Gd-phNO has a considerably large torsion angle around Gd–O–N–C_sp² (69.8(9)° on average) and the largest ferromagnetic coupling parameter (2J/k_B = +18.0(4) K) in Gd–nitroxide compounds ever known. The validity of our molecular design was assessed on the basis of the magneto-structure relation analysis with many literature data including various paramagnetic ligating groups.