Aggregate Manganese Schiff Base Moieties by Terephthalate or Acetate: Dinuclear Manganese and Trinuclear Mixed Metal Mn2/Na Complexes
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- 作者：Changneng Chen ; Deguang Huang ; Xiaofeng Zhang ; Feng Chen ; Hongping Zhu ; Qiutian Liu ; Cunxi Zhang ; Daizheng Liao ; Licun Li ; and Licheng Sun
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：June 2, 2003
- 年：2003
- 卷：42
- 期：11
- 页码：3540 - 3548
- 全文大小：231K
- 年卷期：v.42,no.11(June 2, 2003)
- ISSN：1520-510X
文摘
A reaction system consisting of terephthalic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and salicylidene alkylimineresulted in dinuclear manganese complexes (salpn)2Mn2(
-phth)(CH3OH)2 (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)2Mn2(-phth)(CH3OH)2 (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)2Mn2(-phth)(CH3OH)(H2O) (3), and (salen)2Mn2(-phth) (4), while the absence ofNaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH3OH)(NO3) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H{Mn2Na(salpn)2(-OAc)2(H2O)2}(OAc)2 (6)was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ionswere found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure.Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 wasconsidered to stem from intermolecular magnetic coupling. 1H NMR signals of phenolate ring and alkylene (orphenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidationstates of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchangeinteraction between the Mn(III) sites was observed with J = 1.74 cm-1. A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn2(III)/Mn(III)Mn(II), implying the intactness of the complex backbonein solution.
-phth)(CH3OH)2 (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)2Mn2(-phth)(CH3OH)2 (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)2Mn2(-phth)(CH3OH)(H2O) (3), and (salen)2Mn2(-phth) (4), while the absence ofNaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH3OH)(NO3) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H{Mn2Na(salpn)2(-OAc)2(H2O)2}(OAc)2 (6)was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ionswere found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure.Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 wasconsidered to stem from intermolecular magnetic coupling. 1H NMR signals of phenolate ring and alkylene (orphenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidationstates of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchangeinteraction between the Mn(III) sites was observed with J = 1.74 cm-1. A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn2(III)/Mn(III)Mn(II), implying the intactness of the complex backbonein solution.