o-Iminobenzosemiquinonato complexes of Mn(III) and Mn(IV). Synthesis and characterization of [Mn(III)(L(ISQ))(2)(L(AP))] (S(t) = 1) and [Mn(IV)(L(ISQ))(2)(L(AP)-H)] (S(t) = 1/2).
o-Iminobenzosemiquinonato complexes of Mn(III) and Mn(IV). Synthesis and characterization of [Mn(III)(L(ISQ))(2)(L(AP))] (S(t) = 1) and [Mn(IV)(L(ISQ))(2)(L(AP)-H)] (S(t) = 1/2).
复制标题
Mn(III) 和 Mn(IV) 的邻亚氨基苯并半醌配合物。
DOI：
10.1021/ic010860w
复制
发表时间：
2002
影响因子：
4.6
通讯作者：
K. Wieghardt
中科院分区：
文献类型：
--
作者：
Hyungphil Chun;P. Chaudhuri;T. Weyhermüller;K. Wieghardt
在厌氧条件下，[Mn(III)(3)(micro-O)(micro-CH(3)CO(2))(6)]CH(3)CO(2)(醋酸锰)与2-苯胺基-4，6-二叔丁基苯酚(1：3)在甲醇中反应，以约30%的产率合成了暗棕黑色晶体[Mn(III)(L(Isq))(2)(L(Ap))](1)。(L(AP))(-)代表上述配体的闭壳邻氨基苯酚(-)形式，而(L(Isq))(-)是单阴离子pi自由基形式o-亚氨基苯并二喹酸酯(-)(S(Rad)=1/2)。配合物1可以在(L(AP))(-)配体上去质子化，并在空气中进行单电子氧化，生成[Mn(IV)(L(ISQ))(2)(L(AP)-H)](2)的晶体，其中(L(AP)-H)(2-)表示上述配体的闭壳、双阴离子-氨基苯酸酯(2-)形式。用X-射线单晶衍射法测定了化合物1和2的结构，明确地确定了配体和金属离子的质子化和氧化水平：两个配合物都含有两个pi自由基配体，1个含有一个Mn(III)离子，2个含有一个Mn(IV)离子。自由基团(S(Rad)=1/2)的自旋分别与1和2中的d(4)和d(3)组态发生强烈的反铁磁性耦合，得到1的S=1和2的S=(1)/(2)的基态。这是由温度相关的磁化率测量(2-300K)以及S和X波段的电子顺磁共振谱确定的。
From the reaction of [Mn(III)(3)(micro-O)(micro-CH(3)CO(2))(6)]CH(3)CO(2) (manganese(III) acetate) and 2-anilino-4,6-di-tert-butylphenol (1:3) in methanol under anaerobic conditions, dark brown-black crystals of [Mn(III)(L(ISQ))(2)(L(AP))] (1) were obtained in approximately 30% yield. (L(AP))(-) represents the closed-shell o-aminophenolate(-) form of the above ligand, and (L(ISQ))(-) is the monoanionic pi radical form o-iminobenzosemiquinonate(-) (S(rad) = 1/2). Complex 1 can be deprotonated at the (L(AP))(-) ligand and one-electron-oxidized by air, yielding crystals of [Mn(IV)(L(ISQ))(2)(L(AP)-H)] (2), where (L(AP)-H)(2-) represents the closed-shell, dianionic o-amidophenolate(2-) form of the above ligand. The structures of 1 and 2 have been determined by X-ray crystallography at 100 K. The protonation and oxidation levels of the ligands and of the metal ions have been unequivocally established: both complexes contain two pi radical ligands, 1 contains a Mn(III) ion, and 2 contains a Mn(IV) ion. The spins of the radicals (S(rad) = 1/2) couple strongly antiferromagnetically with the d(4) and d(3) configuration of the Mn ions in 1 and 2, respectively, yielding the observed ground states of S = 1 for 1 and S = (1)/(2) for 2. This has been established by temperature-dependent susceptibility measurements (2-300 K) and S- and X-band EPR spectroscopy.