Rocha Reginaldo C, Shreve Andrew P
Bioscience Division, Mail Stop G755, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Inorg Chem. 2004 Apr 5;43(7):2231-3. doi: 10.1021/ic0354771.
Infrared spectroelectrochemistry has been used to explore the vibrational properties of a pyrazine-bridged osmium-polypyridine dimer as a function of its formally metal-centered oxidation states (i.e., Os(II)Os(II), Os(II)Os(III), and Os(III)Os(III)). The infrared spectrum of the "mixed-valent" species is particularly interesting and exhibits features consistent with both electronic localization and delocalization on the vibrational time scale, as revealed by the presence of both (i) a highly active totally symmetric mode from the bridging pyrazine ligand (nu(8a)), and (ii) total coalescence of at least four modes from peripheral bipyridine ligands. The nature and origin of the observed peaks were confirmed by analysis of the shifts in vibrational frequencies accompanying deuteration of pyrazine and also by comparison of the data for the dimeric complexes with those for the parent monomers.
红外光谱电化学已被用于探究一种吡嗪桥联的锇-多吡啶二聚体的振动性质与其形式上以金属为中心的氧化态（即Os(II)Os(II)、Os(II)Os(III)和Os(III)Os(III)）之间的关系。“混合价态”物种的红外光谱特别有趣，并且表现出与振动时间尺度上的电子定域和离域相一致的特征，这通过以下两点得以揭示：(i) 来自桥联吡嗪配体的一个高活性全对称模式（ν(8a)）的存在，以及 (ii) 至少四个来自外围联吡啶配体的模式完全合并。通过分析吡嗪氘代时伴随的振动频率变化，以及将二聚体配合物的数据与母体单体的数据进行比较，证实了所观察到的峰的性质和起源。
