出版者

長崎大学大学院工学研究科

雑誌

長崎大学大学院工学研究科研究報告 = Reports of Graduate School of Engineering, Nagasaki University (ISSN:18805574)

巻号頁・発行日

vol.52, no.99, pp.30-37, 2022-07

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Aluminum, gallium, indium, and thallium, forming trivalent cations, are r eferred to as earth metals; only Tl also has stable monovalent one. The complexes of Al, for instance, have studied to elucidate industrial use and toxic effects in materials engineering and environmental science. Here, I briefly overview the reported crystal structures of earth metal-complexes chelated by EDTA (ethylenediaminetetraacetic acid) to deepen our knowledge and apply for further research. Bibliographic survey has revealed that 6 of Al-, 14 of Ga-, 6 of In-, and 2 of Tl(III)-EDTA were reported for the crystal structures, showing that the coordination numbers of Al3+ and Ga3+ are 6, In3+ and Tl3+ are 7 in the crystal state. The denticity of EDTA anions are not only hexadentate but also pentadentate (the fourth carboxy group is uncoordinated) in six complexes. A dinuclear Al2-EDTA complex, with two Al3+ bridged by (μ-OH-)2, has a unique cis-conformation of ethylenediamine moiety; it was appeared to have few other analogues.