An inverted triplesalen ligand by a convergent synthesis and its influence on trinuclear FeXII3 complexes

作     者：Bastian FELDSCHER Erich KRICKEMEYER Marc MOSELAGE Hubert THEIL Veronika HOEKE Yvonne KAISER Anja STAMMLER Hartmut BGGE Thorsten GLASER 

作者机构：Lehrstuhl f黵 Anorganische Chemie I Fakult鋞 f黵 Chemie Universit鋞 Bielefeld Universit鋞sstr. 25 D-33615 Bielefeld Germany 

出 版 物：《中国科学：化学》 (SCIENTIA SINICA Chimica)

年 卷 期：2012年第42卷第6期

页      面：897-900页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

主　　题：三核配合物 合成 收敛 反铁磁相互作用 复合物 单晶X-射线衍射 紫外可见光谱 铁配合物 

摘      要：The inverted triplesalen ligand H6feldMehas been synthesized from 2,4,6-triformyl-phloroglucinol and a ketimine salen half-unit in a convergent synthesis. NMR, IR, and UV-vis spectroscopy reveal that this ligand is not in the O-protonated tautomer but in the N-protonated tautomer with substantial heteroradialene contribution. This ligand and the conventional triplesalen ligand H6talent-Bu2 have been used to synthesize the trinuclear FeⅢcomplexes [(feldMe)(FeCl)3] and [(talent-Bu2)(FeCl)3], respectively. The molecular structures of these complexes were obtained by single-crystal X-ray diffraction. Two trinuclear FeⅢcomplexes of [(feldMe)(FeCl)3] dimerize via two Fe-phenolate bonds, whereas due to steric hindrance no dimerization is observed for [(talent-Bu2)(FeCl)3]. The structural data also reveal some heteroradialene contribution in the trinuclear complexes. Whereas UV-vis and M??bauer spectroscopy are not suitable to distinguish between the two complexes, FT-IR spectra show characteristic features due to the different substitution patterns of the conventional and the inverted triplesalen ligands. Another handle is provided by electrochemistry. Whereas both complexes exhibit an irreversible oxidation wave (0.94 V vs. Fc+/Fc for [(feldMe)(FeCl)3] and 0.84 V vs. Fc+/Fc for [(talent-Bu2)(FeCl)3]), which is assigned to the oxidation of the central backbone, higher potential oxidations are reversible for [(talent-Bu2)(FeCl)3]) but irreversible for [(feldMe)(FeCl)3]. This is attributed to the reversible oxidation of the terminal phenolates in the di-tert-butyl substituted [(talent-Bu2)(FeCl)3] in contrast to the mono-methyl-substituted phenolates in [(feldMe)(FeCl)3]. The magnetic properties of [(talent-Bu2)(FeCl)3] reveal a very small ferromagnetic coupling with significant zero-field splitting of the FeⅢS = 5/2 ions. In contrast, the dimerization of two trinuclear complexes in [(feldMe)(FeCl)3] results in antiferromagnetic interactions between the two phenolate-bridged