Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan.
Dalton Trans. 2013 May 14;42(18):6410-6. doi: 10.1039/c3dt00042g.
Heptamethyl (aquo)(pentafluorophenylthiolate)cobyrinate perchlorate, [(H2O)(C6F5S)Cob(III)7C1ester]ClO4, was synthesized as a B12 model complex having a thiolate ligand in the axial position. The axial ligand change in heptamethyl (diaquo)cobyrinate diperchlorate, (H2O)2Cob(III)7C1ester2, from H2O to C6F5S(-) afforded the B12-thiolate complex. The B12-thiolate model complex was characterized by UV-vis, NMR and ESI-mass spectroscopies. The coordination of C6F5S(-) to the cobalt center affected the spectroscopic properties of the corrin ring through the electronic interaction between the axial ligand (C6F5S(-)) and the equatorial ligand (corrin). The photolysis of the B12-thiolate model complex led to the homolytic cleavage of the Co(iii)-S bond to form the Co(II) complex and the phenyl thiyl radical. The thermolysis of the B12-thiolate model complex also led to the homolytic cleavage of the Co(III)-S bond. Furthermore, the reactivity of the Co(III)-S bond of the B12-thiolate model complex was applied to the catalytic oxidation of C6F5SH to C6F5S-SC6F5.
七甲基（偕）（五氟苯硫基）钴卟啉高氯酸盐，[(H2O)(C6F5S)Cob(III)7C1ester]ClO4，是作为具有轴向配体的 B12 模型配合物合成的。在七甲基（偕二水合）钴卟啉高氯酸盐，(H2O)2Cob(III)7C1ester2 中，轴向配体从 H2O 变为 C6F5S(-)，得到了 B12-硫醇配合物。B12-硫醇模型配合物通过 UV-vis、NMR 和 ESI-MS 光谱进行了表征。轴向配体（C6F5S(-)）与赤道配体（卟啉）之间的电子相互作用，影响了卟啉环的光谱性质。B12-硫醇模型配合物的光解导致 Co(iii)-S 键的均裂，形成 Co(II)配合物和苯硫基自由基。B12-硫醇模型配合物的热解也导致了 Co(iii)-S 键的均裂。此外，B12-硫醇模型配合物的 Co(iii)-S 键的反应性被应用于 C6F5SH 的催化氧化为 C6F5S-SC6F5。
