Departamento de Química Inorgánica, Facultade de Ciencias, Universidade de Santiago de Compostela, Lugo, Galicia, Spain.
J Inorg Biochem. 2011 Dec;105(12):1538-47. doi: 10.1016/j.jinorgbio.2011.09.002. Epub 2011 Sep 10.
The peroxidase and catalase activities of eighteen manganese-Schiff base complexes have been studied. A correlation between the structure of the complexes and their catalytic activity is discussed on the basis of the variety of systems studied. Complexes 1-18 have the general formulae MnL(n)(D)(2)(H(2)O/CH(3)OH)(m), where L(n)=L(1)-L(13); D=H(2)O, CH(3)OH or Cl; m=0-2.5 and X=NO(3)(-), Cl(-), ClO(4)(-), CH(3)COO(-), C(2)H(5)COO(-) or C(5)H(11)COO(-). The dianionic tetradentate Schiff base ligands H(2)L(n) are the result of the condensation of different substituted (OMe-, OEt-, Br-, Cl-) hydroxybenzaldehyde with diverse diamines (1,2-diaminoethane for H(2)L(1)-H(2)L(2); 1,2-diamino-2-methylethane for H(2)L(3)-H(2)L(4); 1,2-diamino-2,2-dimethylethane for H(2)L(5); 1,2-diphenylenediamine for H(2)L(6)-H(2)L(7); 1,3-diaminopropane for H(2)L(8)-H(2)L(11); 1,3-diamino-2,2-dimethylpropane for H(2)L(12)-H(2)L(13)). The new Mn(III) complexes MnL(1)(H(2)O)Cl(2.5) (2), MnL(2)(H(2)O)(2)(H(2)O) (4), [MnL(6)(H(2)O)(2)]MnL(6)(CH(3)OH)(H(2)O)(2)(CH(3)OH) (8), MnL(6)(H(2)O)(OAc) (9) and MnL(7)(H(2)O)(2)(CH(3)OH)(2) (12) were isolated and characterised by elemental analysis, magnetic susceptibility and conductivity measurements, redox studies, ESI spectrometry and UV, IR, paramagnetic (1)H NMR, and EPR spectroscopies. X-ray crystallographic studies of these complexes and of the ligand H(2)L(6) are also reported. The crystal structures of the rest of the complexes have been previously published and herein we have only revised their study by those techniques still not reported (EPR and (1)H NMR for some of these compounds) and which help to establish their structures in solution. Complexes 1-12 behave as more efficient mimics of peroxidase or catalase in contrast with 13-18. The analysis between the catalytic activity and the structure of the compounds emphasises the significance of the existence of a vacant or a labile position in the coordination sphere of the catalyst.
研究了十八个锰-Schiff 碱配合物的过氧化物酶和过氧化氢酶活性。根据所研究的系统的多样性，讨论了配合物的结构与其催化活性之间的关系。配合物 1-18 的通式为 MnL(n)(D)(2)(H(2)O/CH(3)OH)(m)，其中 L(n)=L(1)-L(13)；D=H(2)O、CH(3)OH 或 Cl；m=0-2.5 和 X=NO(3)(-)、Cl(-)、ClO(4)(-)、CH(3)COO(-)、C(2)H(5)COO(-)或 C(5)H(11)COO(-)。二价阴离子四齿席夫碱配体 H(2)L(n)是不同取代（OMe-、OEt-、Br-、Cl-）羟基苯甲醛与各种二胺（1,2-二氨基乙烷用于 H(2)L(1)-H(2)L(2)；1,2-二氨基-2-甲基乙烷用于 H(2)L(3)-H(2)L(4)；1,2-二氨基-2,2-二甲基乙烷用于 H(2)L(5)；1,2-二苯基二胺用于 H(2)L(6)-H(2)L(7)；1,3-二氨基丙烷用于 H(2)L(8)-H(2)L(11)；1,3-二氨基-2,2-二甲基丙烷用于 H(2)L(12)-H(2)L(13)）缩合的产物。新的 Mn(III)配合物 MnL(1)(H(2)O)Cl(2.5) (2)、MnL(2)(H(2)O)(2)(H(2)O) (4)、[MnL(6)(H(2)O)(2)]MnL(6)(CH(3)OH)(H(2)O)(2)(CH(3)OH) (8)、MnL(6)(H(2)O)(OAc) (9)和 MnL(7)(H(2)O)(2)(CH(3)OH)(2) (12)被分离并通过元素分析、磁化率和电导率测量、氧化还原研究、ESI 光谱和 UV、IR、顺磁（1）H NMR 和 EPR 光谱进行了表征。这些配合物和配体 H(2)L(6)的晶体结构也有报道。其余配合物的晶体结构以前已经发表过，在这里我们只修订了它们尚未报道的技术（其中一些化合物的 EPR 和（1）H NMR）的研究，这有助于确定它们在溶液中的结构。配合物 1-12 在过氧化物酶或过氧化氢酶的模拟中表现出更高的效率，而 13-18 则不然。对催化活性与化合物结构的分析强调了催化剂配位球中存在空或易变位置的重要性。
