Antiferromagnetic coupling of transition metal spins across pyrimidine and pyrazine bridges in dinuclear manganese(ii), cobalt(ii), nickel(ii) and copper(ii) 1,1,1,5,5,5-hexafluoropentane-2,4-dionate complexes
作者:Takayuki Ishida、Takashi Kawakami、Shin-ichi Mitsubori、Takashi Nogami、Kizashi Yamaguchi、Hiizu Iwamura
DOI:10.1039/b202635j
日期:2002.8.8
Dinuclear manganese(II), cobalt(II), nickel(II), and copper(II) complexes bridged by pyrimidine and pyrazine derivatives, L[M(hfac)2]2 [L = 4,6-di(2-pyridyl)pyrimidine (DPPM), 2,3-di(2-pyridyl)pyrazine (DPPZ); M = Mn, Co, Ni, Cu; hfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dionate], were synthesized and their magnetic properties were studied. Antiferromagnetic couplings across the pyrimidine ring were
双核锰(II),钴(II),镍(II)和铜(II)络合物通过桥联嘧啶 和 吡嗪导数,L [M(hfac)2 ] 2 [L =4,6-二(2-吡啶基)嘧啶 (DPPM), 2,3-二(2-吡啶基)吡嗪(DPPZ);M = Mn,Co,Ni,Cu; 合成了hfac = 1,1,1,5,5,5-六氟戊烷-2,4-二酸酯]并研究了它们的磁性能。观察到用于与所述交换参数,2 DPPM络合物横跨嘧啶环反铁磁耦合Ĵ / ķ乙,的-0.40,-3.1,-9.1和-46 K中分别用M =锰,钴,镍和铜。这嘧啶 氮原子对于M = Mn,Co和Ni,在每个金属离子的轴向位置上进行配位,对于M = Cu,在金属上进行赤道配位。DPPZ配合物还表现出反铁磁相互作用,比DPPM配合物弱。晶体结构分析表明,尽管有不同的空间基团,但四种DPPZ配合物的分子结构基本相同。由于过高估计了DPPM中π型自旋极化的作用,因此DPPM