Дисертації з теми "Molecular solvents"
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Choi, Kwansik. "Molecular interactions in polar solvents." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/17851.
Pradhan, Rajendra. "Molecular interactions in mixtures of some industrially important solvents: a physico-chemical study." Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2698.
Dirama, Taner E. "DYNAMICS OF PROTEINS IN GLASSY SOLVENTS." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133800339.
Parikh, Bhargiv. "Design, Synthesis and Characterization of D-glucosamine Low Molecular Weight Gelators." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1110.
Gohres, John Linton III. "Spectroscopic and computational investigations of molecular interactions in gas-expanded liquids." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24692.
Committee Chair: Charles A. Eckert; Committee Co-Chair: Charles L. Liotta; Committee Member: J. Carson Meredith; Committee Member: Rigoberto Hernandez; Committee Member: William J. Koros
Young, Christi Lynn Patton. "Solute separabilities in solvent gas-rich liquid-liquid-vapor systems topographical and molecular consideration /." Access abstract and link to full text, 1993. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9313535.
Walker, Elaine M. "Modelling the effect of growth envirnoment on the crystallisation of molecular organic compounds." Thesis, University of Strathclyde, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360150.
Saeed, Akhtar. "Static and dynamic light scattering of high molecular weight polystyrene in good solvents." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1059401322.
Struebing, Heiko. "Identifying optimal solvents for reactions using quantum mechanics and computer-aided molecular design." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9150.
Withersby, Matthew Anthony. "Supramolecular architecture of late transition metal co-ordination polymers." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311739.
Masia, Marco. "Solvation dynamics and ion transport in conventional solvents and plasticizers." Doctoral thesis, Universitat Politècnica de Catalunya, 2005. http://hdl.handle.net/10803/6607.
(i) Solvatación y mobilidad ionica. Las características principales del processo de intercambio entre la primera y la segunda capa de hidratación iónica para Li+ en agua se ha encontrado ser independiente del estado termodinamico en gran medida. Ha sido demostrado que el desplazamiento cuadrático medio de moléculas pertenecientes a complejos inertes está caracterizado por un largo transitorio debido a la lenta relajación rotacional del complejo. El incremento del coeficiente de difusión iónico debido a los intecambios en la capa de solvatación ha sido calculado por primera vez en el caso de Li+ y Na+. Finalmente, se han derivado leyes de probabilidad que ponen en relación la estereoquímica y la velocidad iónica instantanea.
(ii) Plastificantes. Se propone un nuevo procedimiento para el desarrollo de campos de fuerza intramoleculares, que funciona satisfactoriamente en el caso de dos moleculas de interés en las Batterias a Iones de Litio: carbonato de etileno y -butirolactona. Respecto a la solvatación de Li+ en los dos solventes, el ión está coordenado por 4 moleculas a través del oxigeno del carbonilo con pequeñas distorsiones de la geometría molecular. La nueva asignación de los modos vibracionales hecha para las dos moléculas ha permitido calcular los cambios inducidos por el ión litio, explicando varias caracteristicas de los espectros esperimentales.
(iii) Polarización. Se ha estudiado la eficacia de los metodos de polarización más comunes para simulaciones de Dinámica Molecular en dímeros ión-molécula, usando calculos ab initio como referencia. En lugar de centrarnos en la superficie de energía potencial completa (procedimiento típico), se ha considerado solo la parte electrostática. Se han desarrollado nuevos modelos polarizables para agua y tetracloruro de carbono, que reproducen el comportamiento de sistemas carga-molécula. Ha sido encontrado que, en el caso de dímeros ión-molécula, se requiere una corrección de amortiguamento de la polarización a cortas distancias. El método de los dipolos puntuales junto al método de amortiguamento de Thole reproduce satisfactoriamente las características principales para cationes y aniones atómicos.
The underlying topic of this thesis is the study of ion solvation by means of computer calculations. Three lines of investigation have been followed:
(i) Solvation and Ionic Mobility. The main features of the exchange process between first and second ionic hydration shells for Li+ in water have been found to be largely independent of the thermodynamic state. It has been shown that the mean square displacement of molecules belonging to inert complexes is characterized by a long transient due to the slow rotational relaxation of the complex. The increase of the ionic diffusion coefficient due to solvation shell exchanges has been computed for the first time in the case of Li+ and Na+. Finally, probability laws have been derived which relate the stereochemistry and the instantaneous ionic velocity.
(ii) Plasticizers. A new approach for the development of intramolecular force fields is proposed, which performs satisfactorily in the case of two molecules of interest for Lithium Ion Batteries: ethylene carbonate and -butyrolactone. Concerning the solvation of Li+ in both solvents, it is coordinated by 4 molecules through the carbonyl oxygen with slight distorsions of the molecular geometry. The new vibrational mode assignment performed for both molecules has allowed to compute the vibrational shifts induced by the lithium ion, explaining a number of features present in the experimental spectra.
(iii) Polarization. The performance of the most commonly used polarization methods for Molecular Dynamics simulation is studied for ion-molecule dimers, using ab initio calculations as benchmark. Instead of focusing on the full potential energy surface (the standard approach), only the electrostatic part is considered. New polarizable models have been developed for water and carbon tetrachloride, which reproduce the behaviour of charge-molecule systems. In the case of ion-molecule dimers it has been found that a polarization damping correction is required at short distances. The point dipole method in conjunction with the Thole damping scheme reproduces rather satisfactorily the main features both for atomic cations and anions.
Eisenhart, Andrew. "Quantum Simulations of Specific Ion Effects in Organic Solvents." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1626356392775228.
Aguilar, Huacan Boris Abner. "Improving of the accuracy and efficiency of implicit solvent models in Biomolecular Modeling." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64409.
Ph. D.
Zhuang, Guorong (Vera). "Application of surface analytical techniques to the study of the reactivity of lithium toward nonaqueous solvents." Case Western Reserve University School of Graduate Studies / OhioLINK, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=case1058811391.
Austin, Nick Donnelly. "Tools for Computer-Aided Molecular and Mixture Design." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/894.
Moreira, Mariana Hoyer. "Modelação e simulação de sistemas envolvendo Deep Eutectic Solvents e água: estruturas, propriedades e extração de poluentes." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/25878.
Nguyen, Thi Ngoc Ha. "TUNING MOLECULAR ARCHITECTURES AT THE LIQUID- SOLID INTERFACE BY CONTROLLING SOLVENT POLARITY AND CONCENTRATION OF MOLECULES." Doctoral thesis, Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-156382.
Nieto, Draghi Carlos Eduardo. "Transport anb Structural Properties of Aqueous Solutions of Organic Solvents." Doctoral thesis, Universitat Rovira i Virgili, 2003. http://hdl.handle.net/10803/8520.
solutions. The peculiar behavior observed in pure water and its mixtures with other substances at different thermodynamic conditions, and the knowledge and understanding of the properties of these systems are the motivations of this work. We have made a direct connection between the local tetrahedral structure of water, created by the presence of hydrogen bonds, and the selfdiffusion coefficient at liquid-like densities. We have found some indications of
an order transition in the three dimensional structure of water at certain conditions of temperature (above 345 K) and densities (between 0.9 to 1.3 g/cm3).
The strong hydrogen bond interaction observed in pure water plays a central role in aqueous solutions. We have studied several properties of aqueous mixtures of associating fluids, such as methanol, ethanol, acetone and dimethyl sulfoxide (DMSO). We observe that the presence of each type of solute perturb the local structure of water in a different manner, and this perturbation gives rise to the formation of chain-like structures with long-range correlation of hydrogen-bonded water molecules that is responsible for the
high viscosity of the mixture. We have also computed the thermal conductivity of the different mixtures, obtaining very good agreement between our simulation results and the available experimental data.
One of the properties that we have analyzed for these binary mixtures is the Ludwing-Soret effect, which is a macroscopic cross effect where a diffusion process is caused by the presence of a temperature gradient in a multicomponent system. This effect can be quantified through the thermal diffusion factor, which is usually positive for most solutions. However, in the
case associating fluids, the value of this coefficient may have a change in its sign at some particular composition. Our simulations reproduce even quantitatively the change in the sign of the Soret coefficient experimentally observed, and to the best of our knowledge, this is the first time that such achievement is reached for a mixture of molecular fluid employing molecular dynamic simulations. Additionally, we have devised a simple lattice model to support the hypothesis that the change in the sign of the Soret coefficient will appear in all cases in which the energy of the crossed interaction between
different species is more negative than the interaction energies between pure components.
The final part of this work is devoted to the computation of structural, transport and dielectric properties of benzene in water at supercritical conditions. We have employed a new Anisotropic United Atom (AUA) model of benzene that reproduces the quadrupolar moment of this molecule. We have computed different properties like self-diffusion coefficient and Maxwell-Stefan
coefficients, and shear viscosity for the mixture at supercritical conditions. A strong density and composition dependence of the properties is observed.
Experimental data shows the presence of aggregates between water and benzene molecules. This fact suggests the presence of some degree of
hydrogen bonding between these two molecules. Our simulations reproduce this behavior and we observed the formation of hydrogen bonds between the two species. In addition, we observe that these bonds are longer lived than the corresponding hydrogen bonds between water molecules. Similarly, we obtain an important reduction of the dielectric constant of the mixture with the increment of the amount of benzene molecules, at least at medium and high
densities.
DE LA TESIS
La simulación Dinámica Molecular ha sido la técnica empleada en este trabajo para la obtención de propiedades de transporte y de equilibrio de sistemas reales. El comportamiento peculiar observado por el agua a diferentes condiciones termodinámicas y en presencia de otras substancias, el conocimiento y entendimiento de las propiedades de este tipo de sistemas son una de las principales motivaciones de este trabajo. Adicionalmente, se ha realizado un extenso estudio de las relaciones intrínsecas existentes entre la estructura local del sistema, desde un punto de vista microscópico, y las
propiedades dinámicas de transporte, tanto en el caso del agua pura como en el caso de mezclas acuosas de solventes orgánicos.
En primer lugar, se ha realizado un análisis de la relación existente entre la estructura local de puentes de hidrógeno presente en el agua pura en condiciones sub y supercríticas, para ello se realizó una comparación entre cuatro diferentes modelos comúnmente utilizados en la literatura. Los resultados obtenidos nos han permitido relacionar de una manera directa la estructura tetraédrica local de las moléculas de agua, creada por la presencia de los puentes de hidrógeno, y el valor que alcanza el coeficiente de autodifusión en condiciones de densidad de líquido.
La fuerte interacción debida a los puentes de hidrógeno presente en las moléculas de agua juega un papel central en el comportamiento de soluciones acuosas. En este trabajo se han estudiado mezclas acuosas de fluidos asociantes, como metanol, etanol, acetona y sulfóxido de dimetilo. El análisis de los resultados de simulación muestra que la presencia de
diferentes tipos de soluto perturban de una manera diferente la estructura tetraédrica local del agua. Esta pérdida en la estructura tetraédrica del agua origina un incremento en la rigidez de las moléculas de agua, con respecto a
otras, más simétricas y menos rígidas, presentes en el agua pura. Como consecuencia, se ha observado un incremento del tiempo de vida de los
puentes de hidrógeno presentes en la mezcla, hecho que justifica el aumento observado en la viscosidad de la mezcla. Por otro lado, se han realizado simulaciones para calcular la conductividad térmica de la mezcla obteniendo
resultados que presentan un acuerdo excelente con los datos experimentales.
El efecto Ludwig-Soret es otra de las propiedades calculadas para las mezclas estudiadas. Este efecto cruzado macroscópico consiste en un
proceso difusivo causado por la presencia de un gradiente de temperatura en sistemas multicomponentes. Este efecto es cuantificado por medio del factor de difusión térmica, el cual suele ser siempre positivo en la mayor parte de
las soluciones. Sin embargo, para el caso de fluidos asociantes, el valor de este coeficiente puede cambiar de signo a una concentración particular. Se ha calculado el coeficiente de Soret para soluciones acuosas de los
compuestos orgánicos antes mencionados. Nuestras simulaciones reproducen el cambio de signo observado en estos sistemas obteniendo un
acuerdo cuantitativo excelente con los datos experimentales. Adicionalmente, se ha podido observar que el cambio de signo en de coeficiente aparece siempre que la energía de interacción cruzada, entre las moléculas de diferentes especies, es mas negativa que las energías de interacción entre los componentes puros.
Finalmente, se han estudiado las propiedades estructurales, dieléctricas y de transporte de mezclas acuosas de benceno en condiciones supercríticas. En nuestras simulaciones se ha utilizado un nuevo modelo anisotrópico de
átomo unificado. Entre las propiedades de la mezcla calculadas se encuentran los coeficientes de auto difusión, difusión de Maxwell-Stefan y
coeficiente de viscosidad en condiciones supercríticas. Adicionalmente, datos experimentales recientes han mostrado la presencia de ciertos grupos de moléculas de benceno y agua formando grupos de agregados. Nuestras simulaciones reproducen la formación de puentes de hidrógeno entre las dos especies con tiempos de vida media superiores a los encontrados entre las moléculas de agua.
Shukla, Charu L. "Computationally Probing the Cybotactic Region in Gas-Expanded Liquids." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14510.
Mohana, Sundaram Hamsa Priya. "Molecular Modeling of Solute/Co-Solvent/Water Preferential Interactions: Toward Understanding the Role of Hydration and Co-solvent in Weak Protein-Protein Interactions." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299609836.
香里, 藤井, and Kaori Fujii. "Time-resolved spectroscopic study on fundamental chemical reactions in a unique class of solvents." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13158494/?lang=0, 2021. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13158494/?lang=0.
In solution, solvent molecules involve chemical reaction of solute molecules and could alter both reaction yield and kinetics. In this thesis, the author focused on fundamental chemical reactions (intermolecular proton transfer and photodissociate reaction) in a unique class of solvents, supercritical fluids and ionic liquids. By measuring time-resolved fluorescence spectrum and transient absorption spectrum of solutes, the author discusses how the reaction yield and kinetics are described by solvent physicochemical properties.
博士(理学)
Doctor of Philosophy in Science
同志社大学
Doshisha University
Smortsova, Yevheniia. "Dye sensitized solar cells efficiency improvement : optimization of the electrolyte using ionic liquids/molecular solvents mixture and study of the photodynamic properties of organic indolinic derivative dyes." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R061/document.
Among all the renewable energy sources, solar energy is the most powerful source far ahead wind or geothermal energies. The first key component of DSSCs is the photosensitizer. It is through this component that the most important steps of photocurrent generation are possible. On the other hand, ionic liquids (ILs) have been proposed as electrolyte for DSSCs due to their peculiar properties: low vapor pressure, high thermal and chemical robustness, tunability of polarity and phase behaviour etc. The objective of this thesis was to get an understanding of the photophysics in the indoline derivated dyes in molecular solvents (MS) and in the IL/MS mixtures. Firstly, the solvent dependence of the spectroscopic properties of D131, D102, D149 and D205 was studied by the steady-state UV-Vis absorption and fluorescence spectroscopy. Then, time-resolved spectroscopy was used to elucidate their photophysics and its solvent dependence. These experiments helped to discern the influence of the hydrogen bond donor and acceptor abilities of the solvent. The solvation dynamics was shown to play a major role in the excited state dynamics of these dyes. This process in IL/MS mixtures was elucidated using the classic fluorescent probe C153 by the means of time-resolved spectroscopy and MD simulations. The complex multi-regime solvation response in these systems was shown to be shaped by the strengthening of the hydrogen bonding between the probe and the mixture components. The results of this thesis work contribute to the fundamental understanding of the photodynamics of the sensitizer and the response of the electrolyte used in the DSSCs
Smortsova, Yevheniia. "Dye sensitized solar cells efficiency improvement : optimization of the electrolyte using ionic liquids/molecular solvents mixture and study of the photodynamic properties of organic indolinic derivative dyes." Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR061.
Among all the renewable energy sources, solar energy is the most powerful source far ahead wind or geothermal energies. The first key component of DSSCs is the photosensitizer. It is through this component that the most important steps of photocurrent generation are possible. On the other hand, ionic liquids (ILs) have been proposed as electrolyte for DSSCs due to their peculiar properties: low vapor pressure, high thermal and chemical robustness, tunability of polarity and phase behaviour etc. The objective of this thesis was to get an understanding of the photophysics in the indoline derivated dyes in molecular solvents (MS) and in the IL/MS mixtures. Firstly, the solvent dependence of the spectroscopic properties of D131, D102, D149 and D205 was studied by the steady-state UV-Vis absorption and fluorescence spectroscopy. Then, time-resolved spectroscopy was used to elucidate their photophysics and its solvent dependence. These experiments helped to discern the influence of the hydrogen bond donor and acceptor abilities of the solvent. The solvation dynamics was shown to play a major role in the excited state dynamics of these dyes. This process in IL/MS mixtures was elucidated using the classic fluorescent probe C153 by the means of time-resolved spectroscopy and MD simulations. The complex multi-regime solvation response in these systems was shown to be shaped by the strengthening of the hydrogen bonding between the probe and the mixture components. The results of this thesis work contribute to the fundamental understanding of the photodynamics of the sensitizer and the response of the electrolyte used in the DSSCs
Kotdawala, Rasesh R. "Adsorption studies of hazardous air pollutants in microporous adsorbents using statistical mechanical and molecular simulation techniques." Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-050407-112429/.
Keywords: Activated carbons; Hydrogen cyanide; Methyl ethyl ketone; Adsorption; Mercury; Monte-Carlo; Solvents; Molecular simulations; Zeolites; Water; Methanol; Nanopores. Includes bibliographical references (leaves 147-150).
Bley, Michael. "Simulating Osmotic Equilibria by Molecular Dynamics - From Vapor-Liquid Interfaces to Thermodynamic Properties in Concentrated Solutions." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS122.
The aim of this PhD thesis is the development of a new theoretical method based on the simulation of vapor-liquid equilibria by means of molecular dynamics (MD) simulation. This new method predicts thermodynamic properties such as solvent activities and solute activity coefficients of aqueous and organic phases used in liquid-liquid extraction systems. These thermodynamic properties are required for mesoscopic thermodynamic modeling approaches estimating the efficiency and selectivity of a given solvent extraction system up to an industrial scale. Thermodynamic and structural properties of aqueous electrolyte solutions and organic solvent phase including aggregates resulting from amphiphilic extractant molecules are reproduced in very good agreement with previously available experimental and theoretical data. The osmotic equilibrium MD approach provides a new and powerful tool for accessing thermodynamic data
Granero-Fernandez, Emanuel. "Fluides supercritiques et solvants biosourcés : propriétés physicochimiques des systèmes expansés par du CO2." Thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/23928/1/Granero%20Fernandez_Emanuel.pdf.
Cavallo, Valentina. "Tailoring intermolecular interactions in methacrylate-based copolymers and nanocomposites : Effect on molecular dynamics and thermal properties." Electronic Thesis or Diss., Lyon, INSA, 2023. http://www.theses.fr/2023ISAL0103.
A correlation between the strength of the intermolecular interactions and physical properties has been reported for amorphous polymers. In particular, an increment of thermal conductivity has been associated to the addition of stronger interactions compared with weak van der Walls, i.e. hydrogen and ionic bonds. In this work, an attempt to tailor thermal conductivity in amorphous polymers has been made by engineering intermolecular interactions. Poly(methylmethacrylate) PMMA was used as standard and poly(methylmethacrylate-co-methacrylic acid) (PMMA-co-MAA) copolymers were synthesised by free radical copolymerization in order to introduce inter-chain hydrogen bonds and, after neutralisation, ionic bonds. Copolymers were successfully obtained up to 30wt% of MAA and characterized. Also, different comonomers were used to evaluate the influence of a flexible unit bringing H-bonds, 2-hydroxyethylmethacrylate (HEMA) or 2-carboxyethylacrylate (CEA). Thermal conductivity slightly increased increasing MAA and HEMA content, while for CEA copolymers the presence of defects prevented the measurement. Later, PMMA-co-MAA was used as a matrix for cellulose-based nanocomposites to tailor filler compatibility, thanks to the presence of H-bonds between MAA unit and cellulose surface. Cellulose nanofibers (CNF) up to 15wt% were efficiently dispersed by solvent casting in a mixture of two solvents (tetrahydrofuran/methanol). Thermal conduction showed no significant changes following the introduction of CNF. Dynamic mechanical analysis (DMA) and broadband dielectric spectroscopy (BDS) were used in combination to fully characterize the macromolecular mobility of PMMA-co-MAA following the introduction of inter-chain H-bonds and the subsequent addition of CNF. An additional β’-relaxation, characterized by an activation energy (Ea) nearly four times higher than the Ea(β), was found for the nanocomposites and ascribed to the establishment of H-bonds between the -COOH groups of the matrix and the hydroxyl groups of CNF, as confirmed by the lower values found for the thermal expansion coefficient of the free volume and the fragility of the material. A deeper investigation about the α-relaxation was able to reveal the influence of CNF confirming the presence of interfacial H-bonds. Indeed, despite the similar glass transition temperatures characterising the matrix and the nanocomposites, a shift of their relaxation times to higher temperatures was observed following the addition of CNF. Results reported in this thesis evidenced that the enhancements of thermal conductivity obtainable by the modification of the interchain interactions between chains in amorphous matrices remains an extremely complex challenge
Cezar, Henrique Musseli. "Implementação e desenvolvimento de algoritmo eficiente para deformação intramolecular com o método Monte Carlo." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-19102018-165856/.
With the increase of computational power in the last decades, the molecular modeling of problems in several areas has become more accessible, being today a fundamental tool used to understand several processes. In particular, molecular simulations with classical force fields have been important for the sampling of thermodynamic properties, for the determination of structures and population of conformers, and for the selection of configurations to be used with methods that combine quantum mechanics with molecular mechanics. The most common simulation methods used nowadays are molecular dynamics (MD) and Monte Carlo (MC). Both methods are in principle equivalent when the goal is configurational sampling, with MD having the advantage of allowing the analysis of the dynamics and temporal evolution, while MC has the advantage of generating the configurations in a probabilistic manner, not necessarily following a path in the potential energy surface, possibly resulting in a more efficient sampling. However, there is no MC methodology that can be considered efficient and established to sample the internal degrees of freedom of molecules with arbitrary complexity. In order to advance in the development of methods that want to achieve this goal, in this work the method presented by Shah e Maginn [1] has been implemented and improved. In the method, the molecule is fragmented into smaller parts, each one composed by the hard degrees of freedom, which do not vary dramatically during the simulation. Those fragments are then connected by soft degrees of freedom, the dihedral and non-bonded terms of the energy. During the simulation the molecule has some of its fragments deleted, and is reconstructed using a Configurational Bias Monte Carlo (CBMC) approach. The contribution of this work to the methodology is generalizing the fragment types within the method, the simplification of the acceptance criteria and some extensions with additional biases, such as electrostatic potential bias and the acceptance criterion of the preferential sampling with the CBMC. The implementation was evaluated through simulations in two simple systems: octane and 1,2-dichloroethane. Comparing the sampling and results obtained for the populations of conformers with MD results, experimental data or values obtained with different MC methods present in the literature, we verified that the implementation reproduces the expected results. Beyond that, the conformational equilibrium of the mesityl oxide (MOx) molecule which has two conformers: syn and anti, was investigated. Due to the potential energy barrier between the two conformers of about 10 kcal/mol, the MD does not perform an ergodic simulation, while the CBMC does the same sampling accordingly. In the CBMC simulation, the inversion of the dominant conformer in gas phase and water was observed. The MOx simulation in acetonitrile and methanol showed that the frequency of the anti conformer indeed increases with the solvent polarity. Nonetheless, due to the stretch of the C = O bond of MOx in methanol, attributed to the hydrogen bonds formed with the solvent, the conformational contribution to the maximum of the absorption band does not follow the polarity tendency, having a larger blue shift in acetonitrile than in methanol. The C = O bond stretch can only be seen because the Cartesian displacement sampling with the Metropolis method was introduced to the original CBMC method. This effect attributed to the stretch is compensated by the solvent, in a way that the total contribution to the transition energy follows the solvent polarity. In general, we conclude that the performance of the developed CBMC method is excellent to the studied cases, being even superior to MD in some cases. The implementation in DICE leaves an important legacy to several research groups, not only for introducing the CBMC method, but also due to general improvements such as parallelization, neighbor list and code modernization, which were introduced during the project.
See, Toh Yoong Hsiang. "Molecular separations with organic solvent nanofiltration." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/11320.
Mandumpal, Jestin Baby. "The molecular mechanism of solvent cryoprotection." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/496.
Damasceno, Marcus Vinicius Araujo. "Estudos dos efeitos de solventes no espectro de absorção eletrônica da merocianina de Brooker e derivados." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-07042015-145330/.
In this thesis we studied the absorption spectrum of merocyanine Brooker (MB) and three derivatives in solvents with different polarities.The interest in this system is given by the presence of some particular properties of this molecule, for example, it presents a large solvatochromic shift due to the change in the polarity of the medium. We present the results for the absorption spectrum of the molecules considering different structures to the ground state: forms trans, cis, zwitterionic (zw), protonated MBH+ and dimer (MB2). The solvent effect was treaty by different ways: (i) continuous model using the PCM polarizable, (ii) by an average electrostatic configuration of solvent, ASEC, (iii) including some explicit solvent molecules with an electrostatic environment generated by other solvent molecules. As an additional investigation, we present results of experimental measurements in the thesis. We have seen, through quantum calculations, that the forms cis/trans have the electronic excitation in the same region and the structural deformation generated in the zw form causes a red shift. Our theoretical and experimental results show that the MBH+ form has a small solvatochromism, with displacement of 20 nm caused by water-chloroform change. Performing spectroscopic titration we got the pKa associated with the process of deprotonation/protonation of MB in water and methanol. In water we obtained a value of 8.7, in good agreement with the values reported in the literature. We present a unpublished pKap for the MB in methanol, 9.9. We got a good theoretical description for electronic excitation of MB in solvents with high polarity, in the region between 430-500 nm, using a method quantum TD-DFT B3LYP and CAM-B3LYP functional whit basic functions set 6-311+G** but the excitation in low polarity solvents, which occurs in the region between 550-650 nm, is not properly described considering the MB form in the solvents. We have seen, through experimental studies that the MB probe can aggregate in low polarity solvents. Theoretical calculations for dimer in solution showed the existence of a low intensity electron excitation in this region. Additionally, the experimental spectra in low polarity solvents showed 2 bands, where in the second band is similar to the observed to MBH+ form. To explain these two experimental bands for MB, we present a theoretical proposal where there is a proton transfer (H+) between the monomers of the dimer, generating a deprotonated structure (MBH-) and a protonated (MBH+). Theoretical calculations for the MBH- show that this form presents an electronic excitation of moderate intensity in the region between 550-650 nm. With this assumption we can describe, through theoretical calculations, the anomalous solvatochromism for the electronic absorption spectrum of MB in the two polarity regions of solvents: high polarity is described by the MB form, and low polarity, described by the MBH- form.
Anim-Mensah, Alexander R. "Evaluation of Solvent Resistant Nano-Filtration (SRNF) Membranes for Small-Molecule Purification and Recovery of Polar Aprotic Solvents for Re-Use." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195148766.
Muchowska, Kamila Barbara. "Molecular balances." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/17880.
Huttenhower, Hillary Anne. "Development of new chemistry for a dual use hydrazine thruster, switchable room temperature ionic liquids, a study of silane grafting to polyethylene and its model compounds, synthesis of the novel hydrazine replacement fuel molecules 1,1-dimethyl-2-[2-azidoethyl]hydrazine and 1,1-dimethyl-2-[2-azidoethyl]hydrazone." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41055.
Radford, Isolde. "Implicit-solvent molecular dynamics simulations of peptide folding." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609804.
González, Yoelvis Orozco. "Fotofísica e propriedades dinâmicas de sistemas moleculares." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-150724/.
The photodynamics of molecular systems represents one of the most important topics of the molecular physical chemistry today. The knowledge of the excited electronic states properties has allowed the development of several important areas, such as the renewable energies, the photomedicine, fluorescent sensors, etc. The aim of this thesis is oriented to the theoretical study of the solvent effect on the photophysics and on the excited electronic states properties of molecular systems. In this thesis, it was initially studied the potential energy surface of the HSO2 molecular system in gas phase and the rotational energy effect on the reactivity of the OH+SO reaction. In the potential energy surface a large number of stationary structures were characterized and it was found a transition state which connects the highest energetic region to the lowest one. Regarding the role of rotational energy on the mentioned reaction, a quasi-classical trajectories study was performed, indicating a decrease in the reactivity when the total rotational energy deposited in the reactants is increased. Subsequently, it was studied the solvent effect on the excited electronic states and on the deactivation mechanisms of three molecular systems, acetone, 1-nitronaphthalene and daidzein. In the acetone molecular system, it was studied the influence of the electronic polarization, caused by the solvent, in the fluorescence spectral shift of the n* excited state. The emission band obtained in water shows a small spectral shift compared to the gas phase, in agreement with the experimental evidences. It was also observed a little dependence of the spectral shift with the degree of the excited state polarization. The 1-nitronaphthalene molecular system was studied to clarify the ultrafast non-fluorescent deactivation mechanism experimentally observed after the absorption transitions, as well as to characterize the transient absorption spectra also observed in the experiments. A very efficient intersystem crossing was found between the first singlet excited state and the second triplet state, which explains the nonfluorescent decay of this molecular system. The proposed deactivation model allows properly describing the transient absorption spectra in methanol and ethanol solvents by absorption transitions from the triplet electronic states. Finally, the daidzein molecular system was studied to understand why in polar protic solvent, such as water, the system is fluorescent, showing a very large Stokes shift value and in polar aprotic solvent, such as acetonitrila, the fluorescence is not observed. In that sense, it was studied the evolution of the excited electronic states in water and in acetonitrile after the absorption transition. The topology of the excited electronic states is different for each solvent, in acetonitrile the system is accessible to a very efficient intersystem crossing that enables the non-fluorescent decay. In water the picture is different, the intersystem crossing is not possible to occur and the system decays by fluorescence to the ground electronic state. In the fluorescent state is observed a considerable electronic polarization that causes the so large Stokes shift value experimentally observed.
Xu, Zhuang. "PARTITIONING OF SOLVENT MOLECULES SURROUNGDING POLYMER CHIANS IN SOLVENT-SHIFTING PROCESS." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1555690517286259.
Lima, Jennifer Dayana Rozendo de. "Interações do CS2 com solventes moleculares." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-18092015-110004/.
In this work has performed a vibrational spectroscopic investigation of carbon disulphide, CS2, neat and in binary mixtures with different molecular solvents, aiming at understanding the solute/solute and solute/solvent interactions. The solvents considered for this study were dichloromethane (CH2Cl2), chloroform (CHCl3), deuterated chloroform (CDCl3), benzene (C6H6) and carbon tetrachloride (CCl4); and the techniques used were Raman and infrared (IR) spectroscopies. The analysis of the Raman bands that compose the Fermi doublet (v1-2v2) allows the determination of a series of empirical values, including the coefficient of Fermi coupling (W), used along this work. The different values of W within the different solvents are consequence of the intermolecular forces between CS2/CS2 and CS2/solvent. The experimental data showed that the W values in all investigated binary mixtures increase as the CS2 molar fraction decreases. It suggests that when CS2 is solvated by different molecules, there is an increase of the anarmonicity, depending on the type of the interaction. The analysis of the band assigned to the CS2 bending mode, v2, performed from infrared spectra, suggests that in the binary mixtures there are two solvation regimes in solution, one related to the CS2/CS2 interactions, where the CS2 molecule is preferentially solvated by CS2 molecules, and one where the CS2 is solvated by the respective solvent molecules.
ĐORĐEVIĆ, LUKA. "Tailoring Organic Matter: from Molecular Design to Functional Supramolecular Species." Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2908098.
Ghosh, Nilanjan. "Structural and associational aspects of some dielectropolar liquid molecules in non polar solvents from relaxation phenomena." Thesis, University of North Bengal, 2002. http://hdl.handle.net/123456789/670.
Adamovic, Ivana. "Solvation!" Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835373-NLtQXD/webviewable/.
Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2009" Ivana Adamovic. 12/19/2004. Report is also available in paper and microfiche from NTIS.
Choi, Jong-Ho Okumura Mitchio Okumura Mitchio. "Infrared spectroscopy of molecular ions and ion-solvent clusters /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-09252007-09111.
Cassiano, Marta Maria. "Dinâmica de Biomoléculas em Água: Simulações com Representação Explícita do Solvente." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/43/43133/tde-21022014-174534/.
The computational package THOR for molecular mechanic and dynamics simulation was improved by the introduction of techniques for modeling of biomolecular systems with explicit representation of solvent molecules. Those techniques include the application of periodic boundary conditions, the use of a cut-off sphere for the potential, with modifications in the electrostatic potential, and the utilization of the method shake to impose distance constraints. Furthermore, a neighbours list was implemented, due to the high number of atoms to be dealt with when the solvent is explicity represented. Simulations were performed on some systems of biological interest, and the influence of the solvent on their conformational properties was analysed. The results are in good agreement with theoretical previsions and experimental data.
Požar, Martina. "On the nature of structural fluctuations in complex liquids." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS269.
The analysis of different types of structuring, present in simple and complex liquids and their mixtures, was done using the method of molecular dynamics. Complex mixtures have at least one associative component, such as water, alcohols (mono-ols and diols) and amines. The supra-molecular structuring in these mixtures is detected, described, quantified and connected with the atom-atom interactions is the molecules. These systems have interesting fluctuation behaviors, as shown through Kirkwood-Buff integrals. Their correlation functions behave in a complex way, depending on the component, concentration and temperature. The pre-peak at small k values in the site-site structure factor is defined as a signature of molecular domains in these mixtures. A special focus is placed on long-range structuring, which is a novelty considering the majority of the work in the field of the physics of liquids. This thesis contributes to a better understanding of micro-heterogeneous structures in molecular liquids, and gives new links to structural heterogeneities in soft and bio-matter
Coutinho, Kaline Rabelo. "Modelo discreto de solvente. Solvatocromismo no espectro de absorção molecular." Universidade de São Paulo, 1997. http://www.teses.usp.br/teses/disponiveis/43/43133/tde-22062012-154558/.
A approach based on the sequential use of Monte Carlo simulation and Quantum Mechanics is proposed and use for the treatment of solvent effects with special attention to solvatochromic shifts. The basic Idea is to perform a classical Monte Carlo simulation to generate supermolecular structures of the system, then to treat these supermolecules (solute, solvent and all its interaction) by quantum mechanics. This is a totally discrete modelo f the solvent that avoids the use of a dielectric continuum. In this approach, the supermolecules are composed by the solute molecule surrounded by the first solvation Shell as determined by the distribution function. The solvent effects are calculated using ensemble average over uncorrelated supermolecular structures obtained by statistical analysis. As na application, the spectral shifts of the 1B2u(- *) trnsition of benzene in different solvents are investigated. Good agreement with the experimental results are obtained.
Adam, Catherine. "Molecular balances for measuring non-covalent interactions in solution." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/16466.
Varma, Pritam S. "Solvent induced NMR chemical shifts that arise from molecular encounters." Thesis, Aston University, 1987. http://publications.aston.ac.uk/9729/.
Böes, Elvis Sidnei. "Estudo teórico da solvatação de ânions em solventes orgânicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/7236.
Youngleson, Jonathan Sinclair. "Molecular genetic characterization of two solvent pathway dehydrogenases from Clostridium Acetobutylicum." Doctoral thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/23245.
Harper, Heather. "Solvent Dependent Molecular Mechanics: A Case Study Using Type I Collagen." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5035.