2016 |
Miranda-Rojas, S; Salazar-Molina, R; Kastner, J; Arratia-Perez, R; Mendizabal, F Theoretical Exploration of Seleno and Tellurophenols as Promising Alternatives to Sulfur Ligands for Anchoring to Gold (111) Materials Artículo de revista Rsc Advances, 6 (6), pp. 4458-4468, 2016, ISSN: 2046-2069. Resumen | Enlaces | BibTeX | Etiquetas: basis-sets, chain-length, charge-transfer, chemistry, complexes, interface, monolayers, nanoparticles, pseudopotentials, self-assembled tellurium titanium @article{RN306, title = {Theoretical Exploration of Seleno and Tellurophenols as Promising Alternatives to Sulfur Ligands for Anchoring to Gold (111) Materials}, author = { S. Miranda-Rojas and R. Salazar-Molina and J. Kastner and R. Arratia-Perez and F. Mendizabal}, url = {/brokenurl#<Go to ISI>://WOS:000369510500023}, doi = {10.1039/c5ra21964g}, issn = {2046-2069}, year = {2016}, date = {2016-01-01}, journal = {Rsc Advances}, volume = {6}, number = {6}, pages = {4458-4468}, abstract = {It is widely known that sulfur ligands, such as alkanethiols or phenothiols and their derivatives, are useful anchor systems for gold materials due to the high affinity of sulfur to gold surfaces. In this study we use DFT calculations and a 42-atom gold cluster model to study the interaction between selenophenol and tellurophenol-derivatives with the Au(111) surface to gain information towards potential new gold-based materials. We modulated the interaction strength by controlling the charge transfer process of a particular interaction by chemically modifying the ligands. To obtain a complete analysis, we studied the ligands in their protonated, anionic and radical states aiming to cover the three possibilities in which these may interact with the gold cluster. In order to get a deeper insight into the nature of the interaction we used several analysis techniques such as energy decomposition analysis (EDA), non-covalent interactions (NCI) and natural population analysis (NPA). Our results reveal that tellurium in the anionic state provides complexes of better thermodynamic stability by similar to 12.0 kcal mol, when compared with the strongest sulfur-gold complex, also in the anionic state. Furthermore, this indicates that the anionic ligand is probably the dominant state for both selenium and tellurium as observed previously for sulfur. The extent to which the interaction strength could be controlled directly depends on the state of the anchor atom. In our case the anionic state is the most suitable for tuning the interaction. Finally, our main findings suggest that exchanging sulfur with selenium or tellurium involves an important increase of the interaction strength, thus, making these selenophenol and tellurophenol derivatives attractive for the development of new functional materials.}, keywords = {basis-sets, chain-length, charge-transfer, chemistry, complexes, interface, monolayers, nanoparticles, pseudopotentials, self-assembled tellurium titanium}, pubstate = {published}, tppubtype = {article} } It is widely known that sulfur ligands, such as alkanethiols or phenothiols and their derivatives, are useful anchor systems for gold materials due to the high affinity of sulfur to gold surfaces. In this study we use DFT calculations and a 42-atom gold cluster model to study the interaction between selenophenol and tellurophenol-derivatives with the Au(111) surface to gain information towards potential new gold-based materials. We modulated the interaction strength by controlling the charge transfer process of a particular interaction by chemically modifying the ligands. To obtain a complete analysis, we studied the ligands in their protonated, anionic and radical states aiming to cover the three possibilities in which these may interact with the gold cluster. In order to get a deeper insight into the nature of the interaction we used several analysis techniques such as energy decomposition analysis (EDA), non-covalent interactions (NCI) and natural population analysis (NPA). Our results reveal that tellurium in the anionic state provides complexes of better thermodynamic stability by similar to 12.0 kcal mol, when compared with the strongest sulfur-gold complex, also in the anionic state. Furthermore, this indicates that the anionic ligand is probably the dominant state for both selenium and tellurium as observed previously for sulfur. The extent to which the interaction strength could be controlled directly depends on the state of the anchor atom. In our case the anionic state is the most suitable for tuning the interaction. Finally, our main findings suggest that exchanging sulfur with selenium or tellurium involves an important increase of the interaction strength, thus, making these selenophenol and tellurophenol derivatives attractive for the development of new functional materials. |
2013 |
Rios, H; Briones, X; Urzúa, M; Vargas, V Cooperative Association of P-Alkylbenzene Sulfonates Sodium Salts to Poly-2-(Dimethylamino) Ethylmethacrylate-N-Alkyl Quaternized at the Water/Chloroform Interface Artículo de revista Journal of Macromolecular Science Part B-Physics, 52 (4), pp. 614-622, 2013, ISSN: 0022-2348. Resumen | Enlaces | BibTeX | Etiquetas: aqueous-solution, association, binding, chloride chloroform-water cooperative counterions, dextran dodecyltrimethylammonium effects, hydrophobic interactions, interface, ions, micelles, polyelectrolyte polyelectrolytes, sulfate, sulfonate surfactant water @article{RN150, title = {Cooperative Association of P-Alkylbenzene Sulfonates Sodium Salts to Poly-2-(Dimethylamino) Ethylmethacrylate-N-Alkyl Quaternized at the Water/Chloroform Interface}, author = { H. Rios and X. Briones and M. Urz\'{u}a and V. Vargas}, url = {/brokenurl#<Go to ISI>://WOS:000313621900008}, doi = {10.1080/00222348.2012.716334}, issn = {0022-2348}, year = {2013}, date = {2013-01-01}, journal = {Journal of Macromolecular Science Part B-Physics}, volume = {52}, number = {4}, pages = {614-622}, abstract = {The association of p-alkyl benzene sulfonate sodium salts with several poly-2-(dimethylamino) ethylmethacrylate-N-alkyl quaternized bromides at the water/chloroform interface was studied. High association percentages were found which increase with both the size of the sulfonate molecule and the length of the polyelectrolyte side chain: octyl, decyl, dodecyl and tetradecyl. The results fit well to the Hill's equation for the association of anionic surfactant to polyelectrolytes. Benzene sulfonate shows an anticooperative behavior for the association, whereas 4-methyl benzene sulfonate and 4-ethylbenzene sulfonate are increasingly cooperative for the association. From the association constants, the standard free energies of transfer from water to the interfacial polyelectrolytes were determined. Their values were a linear function of the number of carbon atoms of the aliphatic residue of the benzene sulfonate molecule ranging from -15.7 kJ/mol of CH2 groups for the octyl polyelectrolyte to -18.9 kJ/mol of CH2 groups for the tetradecyl derivative. These values are similar to those reported for the association of some of these sulfonates molecules with ammonium type cationic micelles. The results for the incremental free energy of transfer by mol of methylene group from water to micelles are in the same order of magnitude as those reported for p-alkyl phenoxides and p-alkylbenzoates to hexadecyltrimethyl ammonium bromide micelles. The results shows that amphipathic counterions as small as 4-ethylbenzenesulfonate are enough to induce a cooperative effect in their association to cationic polyelectrolytes.}, keywords = {aqueous-solution, association, binding, chloride chloroform-water cooperative counterions, dextran dodecyltrimethylammonium effects, hydrophobic interactions, interface, ions, micelles, polyelectrolyte polyelectrolytes, sulfate, sulfonate surfactant water}, pubstate = {published}, tppubtype = {article} } The association of p-alkyl benzene sulfonate sodium salts with several poly-2-(dimethylamino) ethylmethacrylate-N-alkyl quaternized bromides at the water/chloroform interface was studied. High association percentages were found which increase with both the size of the sulfonate molecule and the length of the polyelectrolyte side chain: octyl, decyl, dodecyl and tetradecyl. The results fit well to the Hill's equation for the association of anionic surfactant to polyelectrolytes. Benzene sulfonate shows an anticooperative behavior for the association, whereas 4-methyl benzene sulfonate and 4-ethylbenzene sulfonate are increasingly cooperative for the association. From the association constants, the standard free energies of transfer from water to the interfacial polyelectrolytes were determined. Their values were a linear function of the number of carbon atoms of the aliphatic residue of the benzene sulfonate molecule ranging from -15.7 kJ/mol of CH2 groups for the octyl polyelectrolyte to -18.9 kJ/mol of CH2 groups for the tetradecyl derivative. These values are similar to those reported for the association of some of these sulfonates molecules with ammonium type cationic micelles. The results for the incremental free energy of transfer by mol of methylene group from water to micelles are in the same order of magnitude as those reported for p-alkyl phenoxides and p-alkylbenzoates to hexadecyltrimethyl ammonium bromide micelles. The results shows that amphipathic counterions as small as 4-ethylbenzenesulfonate are enough to induce a cooperative effect in their association to cationic polyelectrolytes. |
2016 |
Theoretical Exploration of Seleno and Tellurophenols as Promising Alternatives to Sulfur Ligands for Anchoring to Gold (111) Materials Artículo de revista Rsc Advances, 6 (6), pp. 4458-4468, 2016, ISSN: 2046-2069. |
2013 |
Cooperative Association of P-Alkylbenzene Sulfonates Sodium Salts to Poly-2-(Dimethylamino) Ethylmethacrylate-N-Alkyl Quaternized at the Water/Chloroform Interface Artículo de revista Journal of Macromolecular Science Part B-Physics, 52 (4), pp. 614-622, 2013, ISSN: 0022-2348. |