Hartl Frantisek, Mahabiersing Taasje, Chardon-Noblat Sylvie, Da Costa Philippe, Deronzier Alain
Molecular Photonic Materials, van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
Inorg Chem. 2004 Nov 1;43(22):7250-8. doi: 10.1021/ic049216i.
IR, UV-vis, and EPR spectroelectrochemistry at variable temperatures and in different solvents were applied to investigate in situ the formation of electroactive molecular chains with a nonbridged Os-Os backbone, in particular, the polymer Os(0)(bpy)(CO)(2) (bpy = 2,2'-bipyridine), from a mononuclear Os(II) carbonyl precursor, [Os(II)(bpy)(CO)(2)Cl(2)]. The one-electron-reduced form, Os(II)(bpy(.)(-))(CO)(2)Cl(2), has been characterized spectroscopically at low temperatures. This radical anion is the key intermediate in the electrochemical propagation process responsible for the metal-metal bond formation. Unambiguous spectroscopic evidence has been gained also for the formation of Os(0)(bpy(*)(-))(CO)(2), the electron-rich electrocatalyst of CO(2) reduction. The polymer species are fairly well soluble in butyronitrile, which is important for their potential utilization in nanoscience, for example, as conducting molecular wires. We have also shown that complete solubility is accomplished for the monocarbonyl-acetonitrile derivative of the polymer, Os(0)(bpy)(CO)(MeCN)(2)Cl.
利用变温及不同溶剂中的红外光谱（IR）、紫外可见光谱（UV-vis）和电子顺磁共振光谱电化学（EPR），原位研究了具有非桥连Os-Os主链的电活性分子链的形成，特别是从单核Os(II)羰基前体[Os(II)(bpy)(CO)₂Cl₂]形成聚合物[Os(0)(bpy)(CO)₂]ₙ（bpy = 2,2'-联吡啶）的过程。单电子还原形式Os(II)(bpy(·)(-))(CO)₂Cl₂已在低温下通过光谱进行了表征。该自由基阴离子是负责金属-金属键形成的电化学传播过程中的关键中间体。对于Os(0)(bpy(*)(-))(CO)₂ₙ（CO₂还原的富电子电催化剂）的形成，也获得了明确的光谱证据。聚合物物种在丁腈中具有相当好的溶解性，这对于它们在纳米科学中的潜在应用（例如作为导电分子线）很重要。我们还表明，聚合物的单羰基-乙腈衍生物[Os(0)(bpy)(CO)(MeCN)₂Cl]ₙ具有完全溶解性。
