Mechanistic Insights into the Formation of Dodecanethiolate-Stabilized Magnetic Iridium Nanoparticles: Thiosulfate vs Thiol Ligands

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• 作者：Diego J. Gavia ; Yeonjin Do ; Jiyeong Gu ; Young-Seok Shon
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：July 3, 2014
• 年：2014
• 卷：118
• 期：26
• 页码：14548-14554
• 全文大小：321K
• ISSN：1932-7455

文摘

The synthesis of stable and isolable iridium nanoparticles with an average core size of 1.2 卤 0.3 nm was achieved by employing sodium S-dodecylthiosulfate as a ligand precursor during the modified Brust鈥揝chiffrin reaction. Transmission electron microscopy (TEM) of the isolated Ir nanoparticles revealed a high degree of monodispersity. Further characterizations with ¹H NMR, FT-IR, UV鈥搗is spectroscopy, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) confirmed that the synthesized Ir nanoparticles are stabilized by dodecanethiolate ligands produced upon the adsorption/cleavage of S-dodecylthiosulfate on the growing Ir nanoparticle surface. By comparison, synthetic attempts employing dodecanethiol as a stabilizing ligand led to the formation of Ir-thiolate species (Ir(SR)₃) as an intermediate and Ir-hydroxide species at the completion of reaction. Mechanistic investigations of these two reactions using S-dodecylthiosulfate and dodecanethiol provided deeper understandings on the novelty of thiosulfate ligands, which allow the successful formation of stable thiolate-capped Ir nanoparticles. Moreover, these Ir nanoparticles were shown to have strong magnetic properties.