摘要
By introduction of a new Fe(L^(1))_(2)spin-crossover(SCO)unit into the polynuclear system,a nano-scale Fe4(L^(2))_(4)molecular square architecture is designed through coordination-directed self-assembly strategy.Both the mononuclear Fe(L^(1))_(2)and tetranuclear Fe4(L^(2))_(4)complexes have bee门structurally confirmed by 1H nuclear magnetic resonance(NMR),electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS),and temperature-dependent single crystal X-ray diffraction studies.Variable-temperature magnetic susceptibility measurements reveal the presence of an abrupt SCO behavior with a thermal hysteresis width of 4K for Fe(L^(1))_(2).By clear contrast,Fe4(L^(2))_(4)undergoes a gradual spin transition behavior with enlarged thermal hysteresis width and higher spin transition temperature.
基金
the National Natural Science Foundation of China(Nos.21825107,21971237,21801241)
the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000).