2016 |
Silva, N; Moris, S; Diaz, M; Yutronic, N; Lang, E; Chornik, B; Kogan, M J; Jara, P Evidence of the Disassembly of Alpha-Cyclodextrin-Octylamine Inclusion Compounds Conjugated to Gold Nanoparticles Via Thermal and Photothermal Effects Artículo de revista Molecules, 21 (11), 2016. Resumen | Enlaces | BibTeX | Etiquetas: beta-cyclodextrin, complex, compounds, constants, core crystals, cyclodextrin, effects, gold inclusion nanoparticles, octylamine, photothermal @article{RN301, title = {Evidence of the Disassembly of Alpha-Cyclodextrin-Octylamine Inclusion Compounds Conjugated to Gold Nanoparticles Via Thermal and Photothermal Effects}, author = { N. Silva and S. Moris and M. Diaz and N. Yutronic and E. Lang and B. Chornik and M.J. Kogan and P. Jara}, url = {/brokenurl#<Go to ISI>://WOS:000389918200026}, doi = {10.3390/molecules21111444}, year = {2016}, date = {2016-01-01}, journal = {Molecules}, volume = {21}, number = {11}, abstract = {Cyclodextrin (CD) molecules form inclusion compounds (ICs), generating dimers that are capable of encapsulating molecules derived from long-chain hydrocarbons. The aim of this study is to evaluate the structural changes experienced by ICs in solution with increasing temperatures. For this, a nuclear magnetic resonance (H-1-NMR) titration was performed to determinate the stoichiometric alpha-cyclodextrin (alpha-CD):octylamine (OA) 2:1 and binding constant (k = 2.16 M-2) of ICs. Solution samples of alpha-CD-OA ICs conjugated with gold nanoparticles (AuNPs) were prepared, and H-1-NMR spectra at different temperatures were recorded. Comparatively, H-1-NMR spectra of the sample irradiated with a laser with tunable wavelengths, with plasmons of conjugated AuNPs, were recorded. In this work, we present evidence of the disassembly of ICs conjugated with AuNPs. Thermal studies demonstrated that, at 114 degrees C, there are reversible rearrangements of the host and guests in the ICs in a solid state. Migration movements of the guest molecules from the CD cavity were monitored via temperature-dependent H-1-NMR, and were verified comparing the chemical shifts of octylamine dissolved in deuterated dimethylsulfoxide (DMSO-d(6)) with the OA molecule included in alpha-CD dissolved in the same solvent. It was observed that, at 117 degrees C, OA exited the alpha-CD cavity. CD IC dimer disassembly was also observed when the sample was irradiated with green laser light.}, keywords = {beta-cyclodextrin, complex, compounds, constants, core crystals, cyclodextrin, effects, gold inclusion nanoparticles, octylamine, photothermal}, pubstate = {published}, tppubtype = {article} } Cyclodextrin (CD) molecules form inclusion compounds (ICs), generating dimers that are capable of encapsulating molecules derived from long-chain hydrocarbons. The aim of this study is to evaluate the structural changes experienced by ICs in solution with increasing temperatures. For this, a nuclear magnetic resonance (H-1-NMR) titration was performed to determinate the stoichiometric alpha-cyclodextrin (alpha-CD):octylamine (OA) 2:1 and binding constant (k = 2.16 M-2) of ICs. Solution samples of alpha-CD-OA ICs conjugated with gold nanoparticles (AuNPs) were prepared, and H-1-NMR spectra at different temperatures were recorded. Comparatively, H-1-NMR spectra of the sample irradiated with a laser with tunable wavelengths, with plasmons of conjugated AuNPs, were recorded. In this work, we present evidence of the disassembly of ICs conjugated with AuNPs. Thermal studies demonstrated that, at 114 degrees C, there are reversible rearrangements of the host and guests in the ICs in a solid state. Migration movements of the guest molecules from the CD cavity were monitored via temperature-dependent H-1-NMR, and were verified comparing the chemical shifts of octylamine dissolved in deuterated dimethylsulfoxide (DMSO-d(6)) with the OA molecule included in alpha-CD dissolved in the same solvent. It was observed that, at 117 degrees C, OA exited the alpha-CD cavity. CD IC dimer disassembly was also observed when the sample was irradiated with green laser light. |
2015 |
Silva, N; Arellano, E; Castro, C; Yutronic, N; Lang, E; Chornik, B; Jara, P Cyclodextrin Inclusion Compound Crystals for Growth of Cu-Au Core-Shell Nanoparticles Artículo de revista Journal of Inclusion Phenomena and Macrocyclic Chemistry, 82 (3-4), pp. 497-504, 2015, ISSN: 1388-3127. Resumen | Enlaces | BibTeX | Etiquetas: alpha-cyclodextrin, complexes compound, copper core-shell decylamine, fabrication, gold inclusion nanoparticles, optical-properties, oxide, particles, phase-transfer, scattering @article{RN248, title = {Cyclodextrin Inclusion Compound Crystals for Growth of Cu-Au Core-Shell Nanoparticles}, author = { N. Silva and E. Arellano and C. Castro and N. Yutronic and E. Lang and B. Chornik and P. Jara}, url = {/brokenurl#<Go to ISI>://WOS:000357572400020}, doi = {10.1007/s10847-015-0531-x}, issn = {1388-3127}, year = {2015}, date = {2015-01-01}, journal = {Journal of Inclusion Phenomena and Macrocyclic Chemistry}, volume = {82}, number = {3-4}, pages = {497-504}, abstract = {The preparation and structural elucidation of the 2 alpha-cyclodextrin/decylamine inclusion compound (IC) by proton nuclear magnetic resonance, rotating frame overhauser effect spectroscopy and powder X-ray diffraction have been achieved. The IC microcrystals were used as a support for the preparation of Au-Cu core-shell nanoparticles by the sputtering method. The coating of copper nanoparticles with gold was verified through anodic stripping voltammetry. The presence of metallic copper and the absence of copper oxides were determined by X-ray photoelectron spectroscopy. These results show that the formation of core-shell Cu-Au by sputtering is an effective approach to prevent the oxidation of Cu particles, leading to potential applications in nanoelectronics.}, keywords = {alpha-cyclodextrin, complexes compound, copper core-shell decylamine, fabrication, gold inclusion nanoparticles, optical-properties, oxide, particles, phase-transfer, scattering}, pubstate = {published}, tppubtype = {article} } The preparation and structural elucidation of the 2 alpha-cyclodextrin/decylamine inclusion compound (IC) by proton nuclear magnetic resonance, rotating frame overhauser effect spectroscopy and powder X-ray diffraction have been achieved. The IC microcrystals were used as a support for the preparation of Au-Cu core-shell nanoparticles by the sputtering method. The coating of copper nanoparticles with gold was verified through anodic stripping voltammetry. The presence of metallic copper and the absence of copper oxides were determined by X-ray photoelectron spectroscopy. These results show that the formation of core-shell Cu-Au by sputtering is an effective approach to prevent the oxidation of Cu particles, leading to potential applications in nanoelectronics. |
2016 |
Evidence of the Disassembly of Alpha-Cyclodextrin-Octylamine Inclusion Compounds Conjugated to Gold Nanoparticles Via Thermal and Photothermal Effects Artículo de revista Molecules, 21 (11), 2016. |
2015 |
Cyclodextrin Inclusion Compound Crystals for Growth of Cu-Au Core-Shell Nanoparticles Artículo de revista Journal of Inclusion Phenomena and Macrocyclic Chemistry, 82 (3-4), pp. 497-504, 2015, ISSN: 1388-3127. |