Phenazineoxonium chloranilatomanganate and chloranilatoferrate: synthesis, structure, magnetic properties, and Mössbauer spectra
Phenazineoxonium chloranilatomanganate and chloranilatoferrate: synthesis, structure, magnetic properties, and Mössbauer spectra
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吩嗪氧鎓氯苯胺锰酸盐和氯苯胺高铁酸盐：合成、结构、磁性和穆斯堡尔谱
DOI：
10.1007/s11172-011-0190-z
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发表时间：
2011
影响因子：
1.7
通讯作者：
V. D. Makhaev
中科院分区：
文献类型：
--
作者：
G. Shilov;Z. Nikitina;N. Ovanesyan;S. Aldoshin;V. D. Makhaev
在丙酮-水-四氢呋喃介质中，金属硫酸盐与氯冉酸和吩嗪（phz）反应，得到了晶体化合物（H3 O）2（phz）3 M2（C6 O 4Cl 2）3·（CH 3COCH 3）n·（H2O）n（n= 0−2，M = Mn（1），Fe（3））。在300、200和150 K下用X射线衍射研究了1的分子和晶体结构。该晶体结构由具有蜂窝结构的聚合阳离子[（H3 O）2（phz）3] n2 n+和阴离子[Mn 2（C6 O 4Cl 2）3] n2 n-层组成，并以形成容纳H2O和CH 3COCH 3溶剂分子的开放式贯通通道的方式堆叠;晶体结构中的H3 O+阳离子是无序的。磁性研究表明Mn 2+离子通过氯冉酸配体发生反铁磁耦合;在T = 5 K时转变为磁有序态。粉末X射线衍射数据表明，配合物3与化合物1具有同构结构，但在电子结构上与化合物1有很大区别。根据Fe ~（57）穆斯堡尔谱，配合物3以离域混合价态Fe ~（2+）/Fe ~（3+）存在，表现出铁磁性质的磁关联和半导体性质的导电性。这些特征归因于Fe 2 ++（C6 O 4Cl 2）2−→ Fe 3 ++（C6 O 4Cl 2）·3−的价态互变异构现象，这是首次在蜂窝结构中观察到的铁。
Crystalline compounds (H3O)2(phz)3M2(C6O4Cl2)3·(CH3COCH3)n·(H2O)n(n= 0−2, M = Mn (1), Fe (3)) were obtained in an acetone-water-tetrahydrofuran medium by the reaction of metal sulfates with chloranilic acid and phenazine (phz). The molecular and crystal structure of1was studied by X-ray diffraction at 300, 200, and 150 K. The crystal structure is composed of polymeric cationic [(H3O)2(phz)3]n2n+and anionic [Mn2(C6O4Cl2)3]n2n−layers having honeycomb structure and stacked in such a way that open-ended through-going channels accommodating H2O and CH3COCH3solvent molecules are formed; the H3O+cations in the crystal structure are disordered. Magnetic studies indicate antiferromagnetic coupling of Mn2+ions through chloranilate ligands; transition to a magnetically ordered state occurs atT= 5 K. According to powder X-ray diffraction data, complex3is isostructural with compound1but differs crucially from1in the electronic structure. According to Fe57Mössbauer spectroscopy, complex3exists in delocalized mixed-valence Fe2+/Fe3+state and, as a consequence, shows ferromagnetic character of magnetic correlations and semiconductor type of electrical conductivity. These features were ascribed to the valence tautomerism Fe2++ (C6O4Cl2)2−→ Fe3++ (C6O4Cl2)·3−, which was observed for the first time for iron in a honeycomb structure.