Triller Michael U, Pursche Daniel, Hsieh Wen-Yuan, Pecoraro Vincent L, Rompel Annette, Krebs Bernt
Institut für Anorganische und Analytische Chemie der Westfälischen Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 8, 48149 Münster, Germany.
Inorg Chem. 2003 Oct 6;42(20):6274-83. doi: 10.1021/ic0347788.
The manganese compounds Mn(bpia)(OAc)(OCH(3)) (1), Mn(bipa)(OAc)(OCH(3)) (2), Mn(bpia)(Cl)(2) (3), Mn(bipa)(Cl)(2) (4), [Mn(Hmimppa)(Cl)(2)] x CH(3)OH (5), and [Mn(mimppa)(TCC)] x 2CHCl(3) (6) (bpia = bis(picolyl)(N-methylimidazole-2-yl)amine; bipa = bis(N-methylimidazole-2-yl)(picolyl)amine; Hmimppa = ((1-methylimidazole-2-yl)methyl)((2-pyridyl)methyl)(2-hydroxyphenyl)amine; TCC = tetrachlorocatechol) were synthesized and characterized by various techniques such as X-ray crystallography, mass spectrometry, IR, EPR, and UV/vis spectroscopy, cyclic voltammetry, and elemental analysis. 1 and 2 crystallize in the triclinic space group Ponemacr; (No. 2), 4 and 6 crystallize in the monoclinic space group P2(1)/n (No. 14), and 5 crystallizes in the orthorhombic space group Pna2(1). Complexes 1-4 are structurally related to the proposed active site of the manganese-dependent extradiol-cleaving catechol dioxygenase exhibiting an N(4)O(2) donor set (1 and 2) or N(4)Cl(2) donor set (3 and 4). Cyclic voltammetric data show that the substitution of oxygen donor atoms with chloride causes a shift of redox potentials to more positive values. These compounds show high catalytic activity regarding the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. The turnover numbers k(cat) = (86 +/- 7) h(-1) (1), k(cat) = (101 +/- 4) h(-1) (2), k(cat) = (230 +/- 4) h(-1) (3), and k(cat) = (130 +/- 4) h(-1) (4) were determined from the double reciprocal Lineweaver-Burk plot. Compounds 5 and 6 can be regarded as structural and electronic Mn analogues for substituted forms of Fe-containing intradiol-cleaving catechol dioxygenases. To our knowledge 5 is the first mononuclear Mn(II) compound featuring an N(3)OCl(2) donor set.
合成了锰化合物Mn(bpia)(OAc)(OCH(3)) (1)、Mn(bipa)(OAc)(OCH(3)) (2)、Mn(bpia)(Cl)(2) (3)、Mn(bipa)(Cl)(2) (4)、[Mn(Hmimppa)(Cl)(2)]·CH(3)OH (5)和[Mn(mimppa)(TCC)]·2CHCl(3) (6)（bpia = 双(吡啶甲基)(N - 甲基咪唑 - 2 - 基)胺；bipa = 双(N - 甲基咪唑 - 2 - 基)(吡啶甲基)胺；Hmimppa = ((1 - 甲基咪唑 - 2 - 基)甲基)((2 - 吡啶基)甲基)(2 - 羟基苯基)胺；TCC = 四氯邻苯二酚），并通过多种技术进行了表征，如X射线晶体学、质谱、红外光谱、电子顺磁共振光谱、紫外/可见光谱、循环伏安法和元素分析。1和2结晶于三斜空间群P1̅（编号2），4和6结晶于单斜空间群P2(1)/n（编号14），5结晶于正交空间群Pna2(1)。配合物1 - 4在结构上与所提出的锰依赖性间苯二酚裂解儿茶酚双加氧酶的活性位点相关，呈现N(4)O(2)供体集（1和2）或N(4)Cl(2)供体集（3和4）。循环伏安数据表明，用氯取代氧供体原子会使氧化还原电位向更正的值移动。这些化合物在将3,5 - 二叔丁基儿茶酚氧化为3,5 - 二叔丁基醌方面表现出高催化活性，在高底物浓度下呈现饱和动力学。通过双倒数Lineweaver - Burk图确定了周转数k(cat) = (86 ± 7) h(-1)（1）、k(cat) = (101 ± 4) h(-1)（2）、k(cat) = (230 ± 4) h(-1)（3）和k(cat) = (130 ± 4) h(-1)（4）。化合物5和6可被视为含铁的间苯二酚裂解儿茶酚双加氧酶取代形式的结构和电子锰类似物。据我们所知，5是第一个具有N(3)OCl(2)供体集的单核Mn(II)化合物。
