Manipulation of Intraparticle Charge Delocalization by Selective Complexation of Transition-Metal Ions with Histidine Moieties

详细信息    查看全文

• 作者：Xiongwu Kang ; Xiang Li ; William M. Hewitt ; Nathaniel B. Zuckerman ; Joseph P. Konopelski ; Shaowei Chen
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：February 21, 2012
• 年：2012
• 卷：84
• 期：4
• 页码：2025-2030
• 全文大小：365K
• 年卷期：v.84,no.4(February 21, 2012)
• ISSN：1520-6882

文摘

Ruthenium nanoparticles were cofunctionalized with pyrene and histidine moieties through Ru鈺恈arbene 蟺 bonds. The selective complexation of the histidine moiety with transition-metal ions led to a marked diminishment of the emission peak at 490 nm which arose from the nanoparticle-bridged pyrene moieties that behaved analogously to pyrene dimers with a conjugated spacer. This is accounted for by the polarization of the core electrons by the added positive charge that impacted the intraparticle charge delocalization between the particle-bound pyrene moieties. This electronic interaction was likely facilitated by the 蟺 interactions between the metal ions and the imidazole ring as well as by the conjugated molecular backbone that linked the imidazole ring to the nanoparticle cores. Within the present experimental context, of all the metal ions tested, the impacts were much more drastic with Pb²⁺, Co²⁺, and Hg²⁺ than with Li⁺, K⁺, Rb⁺, Mg²⁺, Ca²⁺, and Zn²⁺ ions, with the most sensitive variation observed with Pb²⁺. This is ascribed to the enhanced 蟺 interactions of the histidine moiety with the Pb²⁺, Co²⁺, and Hg²⁺ ions because of their capability of donating d electrons, a behavior consistent with prior studies based on conventional histidine-metal ion complexes.