Abstract
Isolable, water-soluble gold clusters protected by monolayers of tiopronin (tiopronin-MPCs) or coenzyme A (CoA-MPCs) were synthesized by a procedure of comparable simplicity to the Brust synthesis for alkanethiolate monolayer-protected gold clusters. High-resolution transmission electron microscopy shows that, like their alkanethiolate-MPC counterparts, the average core diameters of tiopronin-MPCs can be systematically controlled by varying the tiopronin:Au mole ratio employed in the reaction. The UV-vis spectra of tiopronin-MPCs exhibit pH and core size dependency of the surface plasmon band position and intensity, respectively. Thermogravimetric analysis of the tiopronin-MPCs gave average numbers of tiopronin ligands per cluster; for example, tiopronin-MPCs with an average core size of 1.8 nm (∼Au201) are protected with an average of 85 tiopronin ligands. 1H NMR reveals a size-dependent evolution of spectral features interpreted as reflecting differences in attachment sites (terrace, defects) and/or restriction in ligand mobility. Infrared spectroscopy reveals strong hydrogen bonding in the monolayer and provides evidence for intercluster association, and acid/base titrations produce pKA values similar to the free ligand in the presence of a charge-screening supporting electrolyte, but higher in its absence. The same analytical methods were also applied to CoA-MPCs.
| Original language | English |
|---|---|
| Pages (from-to) | 66-76 |
| Number of pages | 11 |
| Journal | Langmuir |
| Volume | 15 |
| Issue number | 1 |
| State | Published - Jan 5 1999 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry
- Physical and Theoretical Chemistry
Cite this
Water-soluble, isolable gold clusters protected by tiopronin and coenzyme a monolayers. / Templeton, Allen C.; Chen, Shaowei; Gross, Stephen; Murray, Royce W.
In: Langmuir, Vol. 15, No. 1, 05.01.1999, p. 66-76.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Water-soluble, isolable gold clusters protected by tiopronin and coenzyme a monolayers
AU - Templeton, Allen C.
AU - Chen, Shaowei
AU - Gross, Stephen
AU - Murray, Royce W.
PY - 1999/1/5
Y1 - 1999/1/5
N2 - Isolable, water-soluble gold clusters protected by monolayers of tiopronin (tiopronin-MPCs) or coenzyme A (CoA-MPCs) were synthesized by a procedure of comparable simplicity to the Brust synthesis for alkanethiolate monolayer-protected gold clusters. High-resolution transmission electron microscopy shows that, like their alkanethiolate-MPC counterparts, the average core diameters of tiopronin-MPCs can be systematically controlled by varying the tiopronin:Au mole ratio employed in the reaction. The UV-vis spectra of tiopronin-MPCs exhibit pH and core size dependency of the surface plasmon band position and intensity, respectively. Thermogravimetric analysis of the tiopronin-MPCs gave average numbers of tiopronin ligands per cluster; for example, tiopronin-MPCs with an average core size of 1.8 nm (∼Au201) are protected with an average of 85 tiopronin ligands. 1H NMR reveals a size-dependent evolution of spectral features interpreted as reflecting differences in attachment sites (terrace, defects) and/or restriction in ligand mobility. Infrared spectroscopy reveals strong hydrogen bonding in the monolayer and provides evidence for intercluster association, and acid/base titrations produce pKA values similar to the free ligand in the presence of a charge-screening supporting electrolyte, but higher in its absence. The same analytical methods were also applied to CoA-MPCs.
AB - Isolable, water-soluble gold clusters protected by monolayers of tiopronin (tiopronin-MPCs) or coenzyme A (CoA-MPCs) were synthesized by a procedure of comparable simplicity to the Brust synthesis for alkanethiolate monolayer-protected gold clusters. High-resolution transmission electron microscopy shows that, like their alkanethiolate-MPC counterparts, the average core diameters of tiopronin-MPCs can be systematically controlled by varying the tiopronin:Au mole ratio employed in the reaction. The UV-vis spectra of tiopronin-MPCs exhibit pH and core size dependency of the surface plasmon band position and intensity, respectively. Thermogravimetric analysis of the tiopronin-MPCs gave average numbers of tiopronin ligands per cluster; for example, tiopronin-MPCs with an average core size of 1.8 nm (∼Au201) are protected with an average of 85 tiopronin ligands. 1H NMR reveals a size-dependent evolution of spectral features interpreted as reflecting differences in attachment sites (terrace, defects) and/or restriction in ligand mobility. Infrared spectroscopy reveals strong hydrogen bonding in the monolayer and provides evidence for intercluster association, and acid/base titrations produce pKA values similar to the free ligand in the presence of a charge-screening supporting electrolyte, but higher in its absence. The same analytical methods were also applied to CoA-MPCs.
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M3 - Article
VL - 15
SP - 66
EP - 76
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 1
ER -