TY - JOUR
T1 - Phase transfer of hydrophilic, cyclodextrin-modified gold nanoparticles to chloroform solutions
AU - Liu, J.
AU - Alvarez, J.
AU - Ong, W.
AU - Román, E.
AU - Kaifer, A. E.
PY - 2001/11/14
Y1 - 2001/11/14
N2 - The preparation and characterization of gold nanoparticles (∼3 nm in diameter) capped with thiolated α- and β-cyclodextrins (α and β-CD) is described. The CD-capped nanoparticles are hydrophilic and bind ferrocene derivatives as evidenced by electrochemical and 1H NMR spectroscopic measurements. The binding interactions of the CD-capped nanoparticles with a series of five alkyldimethyl(ferrocenylmethyl)ammonium ions (the alkyl group is propyl for compound 1, heptyl for 2, dodecyl for 3, hexadecyl for 4, and docosyl for 5) can be utilized for the phase transfer of the hydrophilic, CD-capped nanoparticles into a nonpolar chloroform phase. Only 3, 4, and 5 act as effective phase transfer agents, since 1 and 2 do not have enough amphiphilic character. The structure of the aggregates formed upon transfer of the CD-capped nanoparticles to the chloroform solution is postulated to resemble that of reverse micelles, as the nanoparticles template the peripheral arrangement of the cationic ferrocene amphiphiles, counterions and water molecules around their surfaces.
AB - The preparation and characterization of gold nanoparticles (∼3 nm in diameter) capped with thiolated α- and β-cyclodextrins (α and β-CD) is described. The CD-capped nanoparticles are hydrophilic and bind ferrocene derivatives as evidenced by electrochemical and 1H NMR spectroscopic measurements. The binding interactions of the CD-capped nanoparticles with a series of five alkyldimethyl(ferrocenylmethyl)ammonium ions (the alkyl group is propyl for compound 1, heptyl for 2, dodecyl for 3, hexadecyl for 4, and docosyl for 5) can be utilized for the phase transfer of the hydrophilic, CD-capped nanoparticles into a nonpolar chloroform phase. Only 3, 4, and 5 act as effective phase transfer agents, since 1 and 2 do not have enough amphiphilic character. The structure of the aggregates formed upon transfer of the CD-capped nanoparticles to the chloroform solution is postulated to resemble that of reverse micelles, as the nanoparticles template the peripheral arrangement of the cationic ferrocene amphiphiles, counterions and water molecules around their surfaces.
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U2 - 10.1021/ja003957a
DO - 10.1021/ja003957a
M3 - Article
C2 - 11697957
AN - SCOPUS:0035861033
VL - 123
SP - 11148
EP - 11154
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 45
ER -