Oxomanganese(V) species have been implicated in a variety of biological and synthetic processes, including their role as a key reactive center within the oxygen-evolving complex in photosynthesis. Nearly all mononuclear Mn(V)-oxo complexes have tetragonal symmetry, producing low-spin species. A new high-spin Mn(V)-oxo complex that was prepared from a well-characterized oxomanganese(III) complex having trigonal symmetry is now reported. Oxidation experiments with [FeCp(2)](+) were monitored with optical and electron paramagnetic resonance (EPR) spectroscopies and support a high-spin oxomanganese(V) complex formulation. The parallel-mode EPR spectrum has a distinctive S = 1 signal at g = 4.01 with a six-line hyperfine pattern having A(z) = 113 MHz. The presence of an oxo ligand was supported by resonance Raman spectroscopy, which revealed O-isotope-sensitive peaks at 737 and 754 cm(-1) assigned as a Fermi doublet centered at 746 cm(-1)(Δ(18)O = 31 cm(-1)). Mn Kβ X-ray emission spectra showed Kβ' and Kβ(1,3) bands at 6475.92 and 6490.50 eV, respectively, which are characteristic of a high-spin Mn(V) center.

中文翻译：

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单体高自旋 MnV-Oxo 配合物的制备和性能

Oxomanganese(V) 物种与多种生物和合成过程有关，包括它们作为光合作用中析氧复合物中的关键反应中心的作用。几乎所有单核 Mn(V)-oxo 配合物都具有四方对称性，产生低自旋物质。现在报道了一种新的高自旋 Mn(V)-oxo 配合物，该配合物是由一种具有三角对称性的充分表征的氧锰 (III) 配合物制备的。[FeCp(2)](+) 的氧化实验用光学和电子顺磁共振 (EPR) 光谱进行监测，并支持高自旋氧锰 (V) 复杂配方。并行模式 EPR 频谱在 g = 4.01 处具有独特的 S = 1 信号，具有 A(z) = 113 MHz 的六线超精细图案。共振拉曼光谱支持氧配体的存在，这揭示了 737 和 754 cm(-1) 处的 O 同位素敏感峰，指定为费米双峰，中心位于 746 cm(-1)(Δ(18)O = 31 cm(-1))。Mn Kβ X 射线发射光谱显示 Kβ' 和 Kβ(1,3) 带分别位于 6475.92 和 6490.50 eV，这是高自旋 Mn(V) 中心的特征。