Compared to SO42-(H2O)n, the solute-solvent interaction is favorable by C2O4 2- (H2O)n, n = 6∼12, due to two charges separation and more space in C2O42-. Because of the extensive hydration bonds, the stepwise solvation energy is around 15 kcal/mol even for larger clusters. The solvation dynamics for C 2O42-(H2O)n is influenced by the coupling between torsional movement along C-C bond and solute-solvent interaction. / For Na(H2O)n, the "constant IP" observed experimentally for Na(H2O)n is due to autoionization through Rydberg transition induced by the release of large relaxation energy after the removal of unpaired electron. In contrast, the reorganization is less extensive in Na(NH3)n, as both the electron-NH3 and NH 3-NH3 interactions are weaker, and the structure of Na(NH 3)n is determined by the maximization of Na+-NH 3 interaction. The autoinization is no important and the threshold measured in experiment is indeed for ionization of Na(NH3)n. / In the size-dependant charge separation of SO42-(H 2O)n with n = 3∼7, the key factor governing the charge separation is the difference in the strength of solvation interaction: while interaction with water is strong for SO42- and OH-, it is relatively weak for HSO4-. It gives rise to a barrier for charge separation as SO42- is transformed into HSO4- and OH-, although the overall reaction energy is exothermic. The barrier is high when more than two H2O are left to solvate HSO4-. The entropy is another important factor, which leads to the eventual switch-off of charge separation as cluster size increases. / The equilibrium structures of SO42-(H 2O)n with n = 6∼12 are determined by the competition between the solute-solvent and solvent-solvent interactions. Facilitated by SO42- in symmetry, the extensive hydrogen bonds are formed. The stepwise solvation energy is quite large (often exceeding 15 kcal/mol). AIMD simulation shows "crowding" effects in the first solvation of SO42-(H2O)12 at raised temperature. / The structure and solvation of hydrated di-anion (SO4 2-, C2O42-) clusters and solvated Na clusters are explored computationally by the quantum chemical calculation using Gaussian programme, and by the density functional theory based ab initio molecular dynamics (AIMD) method using Vienna Ab Initio Simulation Package (VASP). / Gao Bing. / "May 2006." / Adviser: Zhi-feng Liu. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6420. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 131-139). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_343724 |
| Date | January 2006 |
| Contributors | Gao, Bing, Chinese University of Hong Kong Graduate School. Division of Chemistry. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xv, 139 p. : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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