Experimental and Theoretical Studies of the Photoreduction of Copper(II)-Dendrimer Complexes

详细信息    查看全文

• 作者：Haiying Wan ; Shenggang Li ; Tatyana A. Konovalova ; Shelby F. Shuler ; David A. Dixon ; Shane C. Street
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：February 7, 2008
• 年：2008
• 卷：112
• 期：5
• 页码：1335 - 1344
• 全文大小：861K
• 年卷期：v.112,no.5(February 7, 2008)
• ISSN：1932-7455

文摘

Zero valent Cu polyamidoamine (PAMAM) dendrimer nanocomposites were synthesized using UV irradiationstarting from the aqueous Cu(II)/dendrimer system. The size of the nanoparticles is strongly dependent onthe generation of the dendrimers and the pH of the solution. Larger nanoparticles are obtained with highergeneration dendrimers, as well as in more basic solution. EPR spectra show that the sites bonded to theCu(II) ion are significantly different at different pH values. Density functional theory (DFT) calculationshave been used to predict the structures and EPR spectra of the Cu(II)-dendrimer complexes. At pH = 3,the hydrated ion complexes Cu(H₂O)₆²⁺ or Cu(H₂O)₅²⁺ are present, as expected and reported previously. AtpH = 7.8, a chelating complex with two tertiary amine sites with or without two amide oxygen sites ispresent. At pH = 11, the Cu(II) ion binds to either the primary amine and amide oxygen sites on a singlebranch or to two tertiary amines and four amide oxygen sites on all four branches. Our results show theimportance of the amide sites in Cu(II)-dendrimer complexes in neutral and basic solutions.