Oxalate-Bridged Bimetallic Complexes {NH(prol)3}[MCr(ox)3] (M = MnII, FeII, CoII; NH(prol)3+ = Tri(3-hydroxypropyl)ammonium) Exhibiting Coexistent Ferromagnetism and Proton Conduction
Oxalate-Bridged Bimetallic Complexes {NH(prol)3}[MCr(ox)3] (M = MnII, FeII, CoII; NH(prol)3+ = Tri(3-hydroxypropyl)ammonium) Exhibiting Coexistent Ferromagnetism and Proton Conduction
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DOI：
10.1021/ja905368d
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发表时间：
2009-09-23
影响因子：
15
通讯作者：
Kitagawa, Hiroshi
中科院分区：
文献类型：
--
作者：
Okawa, Hisashi;Shigematsu, Akihito;Kitagawa, Hiroshi
采用新的合成方法，合成了亲水性三羟丙基铵（NH（prol）（3）（+））与草酸根桥联的三价配合物{NH（prol）（3）}[（MnCrIII）-Cr-II（ox）（3）]（M-II（=）Mn-II，Fe-II，Co-II），研究了NH（prol）（3）（+）离子对配合物结构、磁性和导电性的影响.对MnCr二水合物{NH（prol（3）}[MnCr（ox）（3）]中心点2 H（2）O进行了X射线晶体学研究。晶体数据：六方晶系，P6（3），a = B = 9.3808（14）埃，c = 15.8006（14）埃，Z = 2。该结构包括由NH（prol）（3）（+）离子交错的草酸根桥接的双金属层。离子呈现三脚架结构，并与水分子一起氢键合到双折射层，产生短的层间分离（7.90埃）和双折射层的不对称面。低温磁性研究表明铁磁有序与MnCr复合物的转变温度为5.5 K，9.0 K的FeCr复合物，和10.0 K的CoCr复合物。层间磁相互作用是可以忽略不计的弱在所有的复合物，尽管短的层间分离。在所有的配合物中观察到一个缓慢的磁化。这是由自旋倾斜与非对称性的功能，该层。配合物在40%相对湿度（RH）下显示出1.2 × 10（-10）至4.4 × 10（-10）S cm（-1）的质子传导，在75% RH下类似于1 × 10（-4）S cm（-1）。根据水的吸附/脱附曲线，在40%RH下的传导通过由膜层、NH（prol）（3）（+）离子和水分子（每个MCr两个）形成的氢键网络介导。在75%RH下，额外的水分子（每个MCr三个）与高质子传导有关。这是第一个表现出铁磁性和质子传导共存的金属络合物系统的例子。
The oxalate-bridged bimetallic complexes {NH(prol)(3)}[(MnCrIII)-Cr-II(ox)(3)] (M-II (=) Mn-II, Fe-II, Co-II) with hydrophilic tri(3-hydroxypropyl)ammonium (NH(prol)(3)(+)) were prepared by a new synthetic procedure, and the effects of the NH(prol)(3)(+) ion upon the structure, magnetism, and electrical conduction were studied. An X-ray crystallographic study of the MnCr dihydrate, {NH(prol(3)}[MnCr(ox)(3)]center dot 2H(2)O, was performed. Crystal data: hexagonal, P6(3), a = b = 9.3808(14) angstrom, c = 15.8006(14) angstrom, Z = 2. The structure comprises oxilate-bridged bimetallic layers interleaved by NH(prol)(3)(+) ions. The ions assume a tripodal configuration and are hydrogen bonded to the bimetallic layers together with water molecules, giving rise to a short interlayer separation (7.90 angstrom) and unsymmetrical faces to the bimetallic layer. Cryomagnetic studies demonstrate ferromagnetic ordering with transition temperature of 5.5 K for the MnCr complex, 9.0 K for the FeCr complex, and 10.0 K for the CoCr complex. The interlayer magnetic interaction is negligibly weak in all of the complexes despite the short interlayer separation. A slow magnetization is observed in all the complexes. This is explained by spin canting associated with the unsymmetrical feature of the bimetallic layer. The complexes show proton conduction of 1.2 x 10(-10) to 4.4 x 10(-10) S cm(-1) under 40% relative humidity (RH) and similar to 1 x 10(-4) S cm(-1) under 75% RH. On the basis of water adsorption/desorption profiles, the conduction under 40% RH is mediated through the hydrogen-bonded network formed by the bimetallic layer, NH(prol)(3)(+) ions, and water molecules (two per MCr). Under 75% RH, additional water molecules (three per MCr) are concerned with the high proton conduction. This is the first example of a metal complex system exhibiting coexistent ferromagnetism and proton conduction.