Abstract：
Copper metalloenzymes ascorbate oxidase (AOase), amine oxidase (AmOase), and catechol oxidase (COase) possess copper(II) sites of coordination, which are trimeric, homodimeric, and dimeric, respectively. Two newly mononuclear copper(II) complexes, namely, [Cu(L)(bpy)](ClO4) (1) and [Cu(L)(phen)](ClO4) (2) where HL = Schiff base, have been synthesized. UV-visible, EPR and single-crystal X-ray diffraction examinations were used to validate the geometry in solution and solid state. For complex 1, the metal exhibits a coordination sphere between square pyramidal and trigonal bipyramidal geometry (τ, 0.49). A positive CuII/I redox potential indicates a stable switching between CuII and CuI redox states. Despite the monomeric origin, both homogeneous catalysts (1 or 2) in MeOH were found to favor three distinct chemical transformations, namely, ascorbic acid (H2A) to dehydroascorbic acid (DA), benzylamine (Ph-CH2-NH2) to benzaldehyde (Ph-CHO), and 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) [kcat: AOase, 9.6 (1) or 2.0 × 106 h-1(2); AmOase, 13.4 (1) or 9.4 × 106 h-1 (2); COase, 2.0 (1) or 1.9 × 103 h-1 (2)]. They exhibit higher levels of AOase activity as indicated by their kcat values compared to the AOase enzyme. The kcat values for COase activity in buffer solution [5.93 (1) or 2.95 × 105 h-1 (2)] are one order lower than those of the enzymes. This is because of the labile nature of the coordinated donor, the flexibility of the ligand, the simplicity of the catalyst-substrate interaction, and the positive CuII/I redox potential. Interestingly, more efficient catalysis is promoted by 1 and 2 concerning that of other mono- and dicopper(II) complexes.
摘要：
铜金属酶抗坏血酸氧化酶（AOase），胺氧化酶（AmOase），儿茶酚氧化酶（COase）具有铜（II）配位位点，是三聚体的，同二聚体，和二聚体，分别。两个新的单核铜（II）配合物，即,[Cu（L）（bpy）]（ClO4）（1）和[Cu（L）（phen）]（ClO4）（2）其中HL=希夫碱，已经合成了。UV-可见光,EPR和单晶X射线衍射检查用于验证溶液和固态的几何形状。对于配合物1，金属在方形锥体和三角形双锥体几何之间表现出配位球（τ，0.49)。正的CuII/I氧化还原电势表明CuII和CuI氧化还原态之间的稳定转换。尽管单体起源，发现两种均相催化剂(1或2)在MeOH中有利于三种不同的化学转化，即,抗坏血酸（H2A）到脱氢抗坏血酸（DA），苄胺（Ph-CH2-NH2）到苯甲醛（Ph-CHO），和3,5-二叔丁基邻苯二酚（3,5-DTBC）至3,5-二叔丁基醌（3,5-DTBQ）[kcat：AOase，9.6（1）或2.0×106h-1（2）；酶，13.4（1）或9.4×106h-1（2）；科斯，2.0(1)或1.9×103h-1(2)]。与AOase酶相比,它们表现出更高水平的AOase活性,如它们的kcat值所示。缓冲溶液中COase活性的kcat值[5.93（1）或2.95×105h-1（2）]比酶的kcat值低一个数量级。这是因为协调供体的不稳定性质，配体的灵活性，催化剂-底物相互作用的简单性，和正CuII/I氧化还原电位。有趣的是,1和2促进了更有效的催化，涉及其他单-和decopper（II）配合物。
