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You searched for subject:(alkali metal cations). Showing records 1 – 2 of 2 total matches.

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University of Surrey

1. Zapata-Ormachea, Mariel L. Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state.

Degree: PhD, 2000, University of Surrey

This thesis concerns the thermodynamics of macrocycles and their metal cation complexes in non-aqueous media and these are discussed under two main headings, i) Thermodynamics of Alkali-Metal Cations and Macrocycles in Solution and in the Solid State. Thermodynamic parameters of complexation for alkali-metal cations and macrocycles (18-crown-6 and ethyl p-tert-butylcalix(6)arene hexanoate) in benzo-nitrile at 298.15 K are first reported. These data are compared with those previously reported for cryptand 222 and these cations in this solvent. A 'peak' selectivity for potassium is observed for the complexation of the calix(6)arene ester with alkali metal cations. The process is enthalpy controlled with an exothermic maximum for the potassium cation. Thermodynamic data of complexation are characterised by a lower enthalpic stability and a more favourable entropy (except for K+) than corresponding data involving cryptand 222 or indeed 18-crown-6. Standard enthalpies of solution, DeltasH0, of macrocycles and their sodium and potassium salts in benzonitrile measured calorimetrically are discussed in relation to (i) data for the uncomplexed salts and (ii) previously reported data for sodium and potassium cryptate salts in various solvents. Enthalpies of coordination, DeltacoordH0, for eighteen systems involving sodium and potassium coronates, cryptates and calix(6)arenates are derived and whenever possible these are discussed on the basis of (i) available X-ray crystallographic data and (ii) the anion effect on the coordination process. ii) Thermodynamics of Lower Rim Calix(4)arene Derivatives with the Silver Cation in Different Media at 298.15 K. The DeltasH0 values of p-tert-butyl(bis-diethylamine-bis-methysulphanyl) calix(4)arene (EATCalix4) in various solvents at 298.15 K are reported. Transfer parameters from acetonitrile to other solvents are calculated. The interaction of EATCalix4 and the silver cation was investigated by 1H NMR in deuterated acetonitrile at 298 K showing that the ligand hosts the metal cation through interaction with the different donor atoms (O, N, S). Conductimetric titrations indicate that the stoichiometry of the complex is 1:1. The thermodynamics of complexation of EATCalix4 and silver in six solvents at 298.15 K is reported. The DeltasH0 values of the free and the complex silver perchlorate salts have been also measured in various solvents and these have been combined with DeltacH0 data to derive the DeltacoordH0 of this system. A few representative examples about the use of coordination data are given. The medium effect on the complexation process is assessed in terms of DeltatG0, DeltatH0 and DeltatS0 of the reactants and the product from acetonitrile to the appropriate solvent. The relevance of analysing the solvation changes that these species undergo upon complexation is emphasised.

Subjects/Keywords: 547; Alkali-metal cations; Calixarene; Ligands

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zapata-Ormachea, M. L. (2000). Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state. (Doctoral Dissertation). University of Surrey. Retrieved from http://epubs.surrey.ac.uk/843197/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340417

Chicago Manual of Style (16th Edition):

Zapata-Ormachea, Mariel L. “Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state.” 2000. Doctoral Dissertation, University of Surrey. Accessed October 18, 2019. http://epubs.surrey.ac.uk/843197/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340417.

MLA Handbook (7th Edition):

Zapata-Ormachea, Mariel L. “Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state.” 2000. Web. 18 Oct 2019.

Vancouver:

Zapata-Ormachea ML. Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state. [Internet] [Doctoral dissertation]. University of Surrey; 2000. [cited 2019 Oct 18]. Available from: http://epubs.surrey.ac.uk/843197/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340417.

Council of Science Editors:

Zapata-Ormachea ML. Thermodynamic aspects of macrocycles and their metal-ion complexes in solution and in the solid state. [Doctoral Dissertation]. University of Surrey; 2000. Available from: http://epubs.surrey.ac.uk/843197/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340417


The Ohio State University

2. Coons, Marc P. L. Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface.

Degree: PhD, Chemistry, 2017, The Ohio State University

Liquid microjet photoelectron spectroscopy is a state-of-the-art experimental technique that provides avenues for investigating ultrafast charge and energy transfer processes in liquid water and aqueous solutions. The emphasis of this work is placed on making contact with recent liquid microjet experiments of hydrated electrons, e-(aq), in liquid water and at the liquid-vapor interface from a computational perspective. Since its discovery nearly 55 years ago, e-(aq) has attracted significant attention from both experimental and theoretical communities due to its crucial role in radiation chemistry and its relatively elusive structure in liquid water at ambient conditions. Historically, the primary observable of hydrated electrons has been a well-characterized optical absorption spectrum, but with the advent of liquid microject spectroscopy, this has shifted to measurements of its relative binding energy below vacuum level. Some experiments utilizing this methodology have been interpreted to suggest that e-(aq) at the liquid-vapor interface is energetically dissimilar than in liquid water, and that, unlike the more strongly bound species in liquid, it can potentially undergo destructive reactions with solvated DNA molecules.A variety of computational strategies are employed to demonstrate that the spectroscopic properties of hydrated electrons in liquid water are actually quite similar to the interfacial species. To that end, mixed quantum-classical molecular dynamics simulations are performed where e-(aq) in liquid water and at the interface is described by two different one-electron pseudopotentials. These simulations suggest that the presence of e-(aq) at a liquid-vapor interface is fleeting at ambient conditions, and to experimentally distinguish it from the bulk species using standard spectroscopic techniques would be challenging. Non-equilibrium polarizable continuum models (PCMs), in conjunction with MP2 and DFT methods, are then employed to compute vertical ionization energies in liquid water. However, computing these quantities in anisotropic environments, such as at an interface, is not possible with traditional PCMs. Therefore, a novel methodology is presented for computing vertical ionization energies at a liquid-vapor interface that has developed to incorporate non-equilibrium solvent polarization effects for molecules immersed in arbitrary dielectric environments. This method is applied to e-(aq), alkali metal cations, and halide anions in liquid water, for which vertical ionization energies have been measured, and also to predict these quantities at the interface where some liquid microjet measurements do not yet exist. Advisors/Committee Members: Herbert, John (Advisor).

Subjects/Keywords: Chemistry; Physical Chemistry; hydrated electrons; alkali metal cations; halide anions; vertical electron binding energy; vertical ionization potential; continuum solvation models; DFT; MP2; mixed quantum-classical simulations; multigrid method

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Coons, M. P. L. (2017). Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1503014629752161

Chicago Manual of Style (16th Edition):

Coons, Marc P L. “Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface.” 2017. Doctoral Dissertation, The Ohio State University. Accessed October 18, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503014629752161.

MLA Handbook (7th Edition):

Coons, Marc P L. “Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface.” 2017. Web. 18 Oct 2019.

Vancouver:

Coons MPL. Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface. [Internet] [Doctoral dissertation]. The Ohio State University; 2017. [cited 2019 Oct 18]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1503014629752161.

Council of Science Editors:

Coons MPL. Solvent Effects for Vertical Ionization Processes in Liquid Water and at the Liquid-Vapor Interface. [Doctoral Dissertation]. The Ohio State University; 2017. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1503014629752161

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