A POLYMERIC 2-DIMENSIONAL MIXED-METAL NETWORK - CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF ([P(PH)4][MNCR(OX)3])N
A POLYMERIC 2-DIMENSIONAL MIXED-METAL NETWORK - CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF ([P(PH)4][MNCR(OX)3])N
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DOI：
10.1016/0020-1693(93)03711-i
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发表时间：
1994-02-01
影响因子：
2.8
通讯作者：
HAUSER, A
中科院分区：
文献类型：
--
作者：
DECURTINS, S;SCHMALLE, HW;HAUSER, A
制备了混合金属铁磁体{[P（Ph）4][MnCr（ox）3]}n，其中Ph为苯基，ox为草酸根，并由单晶X射线数据确定了由Mn（II）-ox-Cr（III）桥延伸的二维网络结构。晶体数据：空间群R3 c，a = B = 18.783（3），c = 57.283（24）埃，α = β = 90，γ = 120度，Z=24（C30 H20 O 12 PCrMn）。在260-20 K温度范围内，磁化率数据服从居里-韦斯定律，外斯韦斯常数为10.5 K。在T（c）= 5.9K时，样品的摩尔磁化强度随温度的变化表现出磁相变。讨论的结构有关的战略，用于制备基于分子的铁磁体，此外，它是一个解决方案的问题的维数的[MM '（ox）3]n网络，这在原则上可以扩展到二维或三维的晶格。单晶的吸收光谱归属于CrO_6发色团。它们的极化模式反映了D3对称性的电偶极子选择规则。一个强大的网站选择性发光从铬（III）2 E状态观察到在低温下，该系统可能是适合于研究能量转移机制。
The mixed-metal ferromagnet {[P(Ph)4][MnCr(ox)3]}n, where Ph is phenyl and ox is oxalate, has been prepared and a two-dimensional network structure, extended by Mn(II)-ox-Cr(III) bridges, has been determined from single crystal X-ray data. Crystal data: space group R3c, a = b = 18.783(3), c = 57.283(24) angstrom, alpha = beta = 90, gamma = 120-degrees, Z=24 (C30H20O12PCrMn). The magnetic susceptibility data obey the Curie-Weiss law in the temperature range 260-20 K with a positive Weiss constant of 10.5 K. The temperature dependence of the molar magnetization exhibits a magnetic phase transition at T(c) = 5.9 K. The structure is discussed in relation to the strategy for preparing molecular based ferromagnets and, in addition, it is a solution to the question of the dimensionality of the [MM'(ox)3]n network, which in principle can extend two- or three-dimensionally to the crystal lattice. The optical absorption spectra of the single crystals are assigned to the 'CrO6' chromophores. Their polarization patterns reflect the electric dipole selection rules for D3 symmetry. A strong site selective luminescence from the chromium(III) 2E states is observed at low temperature and the system may be suitable for studying energy transfer mechanisms.