Striking Confinement Effect: AuCl[subscript 4][superscript -] Binding to Amines in a Nanocage Cavity

Journal Article · Mon Feb 23 00:00:00 EST 2009 · J. Am. Chem. Soc.

DOI:https://doi.org/10.1021/ja806179j· OSTI ID:1007054

Henao, Juan D; Suh, Young-Woong; Lee, Jeong-Kyu; Kung, Mayfair C; Kung, Harold H ^[1]

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1. NWU

Binding of AuCl{sub 4}{sup -} to amine groups tethered to the interior of a 2 nm siloxane nanocage was determined in solutions containing various concentrations of acid. The mode of binding was inferred from EXAFS and UV-vis spectra to be by ligand exchange of amine for chloride, which implies that the amines remain unprotonated. Cyclic voltammetry confirmed that the Au complexes bind to the nanocage interior and established a 1:1 relationship between bound Au complex and amine groups. The results suggested a 5-7 pH unit shift in the protonation constant of the interior amines relative to free amines in solution.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USDOE
• OSTI ID: 1007054
• Journal Information: J. Am. Chem. Soc., Vol. 130, Issue (48) ; 2008; ISSN 0002-7863
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMINES
CONFINEMENT
ION EXCHANGE
LIGANDS
SILOXANES
SPECTRA