Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
Dalton Trans. 2023 Jun 13;52(23):7836-7842. doi: 10.1039/d3dt00955f.
We show that a new terpyridine ligand comprising a directly-connected methyldisulfide group (tpySSMe) can be used to prepare a modular series of metal bis(terpyidine) complexes, M(tpySSMe) (M = Fe, Co, Zn), suitable for the functionalization of metal surfaces. Critically, we find these complexes are air-stable in solution for >7 d, in stark contrast to their thiol-substituted analogues, M(tpySH) (M = Fe, Co), which decompose in <1 d. While CoSH has previously been utilized in several important studies, we explicitly detail its synthesis and characterization here for the first time. We subsequently probe the electrochemical properties of M(tpySSMe) in solution, showing that the (electro)chemical reactions associated with disulfide reduction significantly increase the complexity of the voltammetric response. In preliminary surface voltammetry studies, we confirm that CoSS and FeSS form solution-stable self-assembled monolayers (SAMs) on gold with comparable electrochemical properties to those formed from CoSH. Taken together, this work provides a robust foundation for future studies of this prominent class of complexes as redox-active components of SAMs or single-molecule junctions.
我们表明，一种新的包含直接连接的甲硫基二硫化物基团（tpySSMe）的三吡啶配体可用于制备一系列模块化的金属双（三吡啶）配合物[M（tpySSMe）]（PF）（M = Fe，Co，Zn），适合金属表面的功能化。至关重要的是，我们发现这些配合物在溶液中> 7 d 是空气稳定的，与它们的硫醇取代类似物[M（tpySH）]（PF）（M = Fe，Co）形成鲜明对比，后者在<1 d 内分解。虽然 CoSH 已在几项重要研究中得到应用，但我们在这里首次明确详细介绍了其合成和表征。随后，我们研究了[M（tpySSMe）]（PF）在溶液中的电化学性质，表明与二硫化物还原相关的（电）化学反应显著增加了伏安响应的复杂性。在初步的表面伏安研究中，我们证实 CoSS 和 FeSS 在金上形成具有类似电化学性质的稳定自组装单层（SAM），与 CoSH 形成的 SAM 相当。总之，这项工作为将来将这类重要配合物作为 SAM 或单分子结的氧化还原活性组件进行研究提供了坚实的基础。
