Ferrimagnetic ordering of a methylthio-substituted planar porphyrin based electron transfer salt, octakis(2,3,7,8,12,13,17,18-methylthio)porphyrinatomanganese(iii) tetracyanoethanide
作者:Ken-ichi Sugiura、Kantaro Ushiroda、Mitchell T. Johnson、Joel. S. Miller、Yoshiteru Sakata
DOI:10.1039/b006261h
日期:——
The direct redox reaction between tetracyanoethylene (TCNE) and
a planar porphyrinatomanganese(II), octakis(2,3,7,8,12,13,17,18-methylthio)porphyrinatomanganese(II),
MnIIOMTP, produced a polymeric electron transfer salt (ETS), that
has been structurally and magnetically characterized. The ETS belongs to the
orthorhombic Cmca space group. The ETS has an extended one-dimensional
linear chain coordination polymer motif comprised of S = 2
[MnIIIOMTP]+ and bridging S = 1/2
[TCNE]−˙ with an Mn–NTCNE distance
of 2.330(5) Å, and lacks solvent. The [TCNE]−˙
is disordered over two orientations in a 1 ∶ 1 ratio. The
interchain Mn⋯Mn distance, 9.205 Å, is shorter than the
intrachain distance, 9.350 Å (≡a-axis). The
2 to 300 K temperature dependence of the magnetic susceptibility can
be fit to a Curie–Weiss expression with an effective θ
value of +40 K. Intrachain coupling was modelled to a Seiden expression
(H = −2Sa·Sb)
with a Jintra of −125 K, and 10 Hz
ac magnetic susceptibility indicates an ordering temperature, Tc,
of 9.6 K. The frequency dependence of the ac susceptibility displays
spin glass behaviour.
四氰基乙烯(TCNE)与平面卟啉锰(II)--八(2,3,7,8,12,13,17,18-甲硫基)卟啉锰(II)--MnIIOMTP--之间的直接氧化还原反应生成了一种聚合物电子转移盐(ETS),并对其结构和磁性进行了表征。ETS 属于正交 Cmca 空间群。ETS 具有扩展的一维线性链配位聚合物图案,由 S = 2 [MnIIIOMTP]+ 和桥接 S = 1/2 [TCNE]-˙组成,Mn-NTCNE 间距为 2.330(5)埃,并且缺乏溶剂。TCNE]-˙ 以 1 ∶ 1 的比例在两个方向上无序分布。链间 Mn⋯Mn 距离 9.205 Å 短于链内距离 9.350 Å(≡a 轴)。链内耦合根据 Jintra 为 -125 K 的 Seiden 表达式(H = -2Sa-Sb)建模,10 Hz 交流磁感应强度表明有序温度 Tc 为 9.6 K。