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Development and Application of a First Principle Molecular Model for Solvent Effects

Öhrn, Anders LU (2008)
Abstract (Swedish)
Popular Abstract in Swedish

En betydande del av kemin i naturen och inom industrin äger rum i en omgivning av andra molekyler. Reaktioner, övergångar, interaktioner och andra kemiska processer påverkas nästan alltid utav omgivningen. Dessa modifikationer eller omgivningseffekter beror i grund och botten på växelverkan mellan molekylerna, den så kallade intermolekylära växelverkan. Det speciella fallet med effekter från ett lösningsmedel, likt vatten, kallas lösningsmedelseffekter och har studerats omfattande och används för att finjustera egenskaper hos kemiska processer.



I denna avhandling studeras lösningsmedelseffekter teoretiskt. Med datorsimuleringar kan grunläggande frågor om vissa givna effekter,... (More)
Popular Abstract in Swedish

En betydande del av kemin i naturen och inom industrin äger rum i en omgivning av andra molekyler. Reaktioner, övergångar, interaktioner och andra kemiska processer påverkas nästan alltid utav omgivningen. Dessa modifikationer eller omgivningseffekter beror i grund och botten på växelverkan mellan molekylerna, den så kallade intermolekylära växelverkan. Det speciella fallet med effekter från ett lösningsmedel, likt vatten, kallas lösningsmedelseffekter och har studerats omfattande och används för att finjustera egenskaper hos kemiska processer.



I denna avhandling studeras lösningsmedelseffekter teoretiskt. Med datorsimuleringar kan grunläggande frågor om vissa givna effekter, deras molekylära ursprung i andra ord, tas itu med. En ny modell med detta syftet formuleras i avhandlingen. Modellen utvecklas från grundläggande relationer och väletablerad kunskap om intermolekylär växelverkan, statistisk mekanik och kvantmekanik. Ingen experimentell data används som input till modellen, istället är modellens utgångspunkt teoretiska grundprinciper. I diskussionen av modellen läggs särskild tonvikt på frågan om balans mellan de ingående approximationerna.



Modellen visas förmå reproducera välkaraktäriserade experimentella data för några testsysten. Modellen används också till att studera solvation och fotokemiska processer för vilka experiment av idag ej förmår klargöra det molekylära ursprunget. Särskilt anmärkningsvärda resultat från dessa studier är: asymmetrisk solvation av den kvadrupolära para-bensokinon, gränssnittsspecifika effekter på indols spektra vid luft/vatten-gränssnittet, kopplingar mellan polarisation och repulsion i solvationen av monoatomära joner, samt signifikant beroende på omgivningens egenskaper för ureas molekylärstruktur. (Less)
Abstract
A considerable part of chemistry in nature and industry, takes place in an environment of other molecules. Reactions, transitions, interactions or other chemical processes are almost always modified by the environment. These modifications or environment effects depend ultimately on the interactions between the molecules, the so called intermolecular interactions. The special case of effects induced by a solvent, such as water, are called solvent effects, and are widely studied and used to fine-tune properties of chemical processes.



In this thesis, solvent effects are studied theoretically. Fundamental questions of how certain effects come about, that is their molecular origin, can be addressed through computer... (More)
A considerable part of chemistry in nature and industry, takes place in an environment of other molecules. Reactions, transitions, interactions or other chemical processes are almost always modified by the environment. These modifications or environment effects depend ultimately on the interactions between the molecules, the so called intermolecular interactions. The special case of effects induced by a solvent, such as water, are called solvent effects, and are widely studied and used to fine-tune properties of chemical processes.



In this thesis, solvent effects are studied theoretically. Fundamental questions of how certain effects come about, that is their molecular origin, can be addressed through computer simulations. A new model with this purpose is formulated in the thesis. The model is developed from fundamental relations and well-established knowledge of intermolecular interactions, statistical mechanics and quantum mechanics. No experimental data are used as input into the model, rather the model proceeds from theoretical first principles. In the discussion of the model, special attention is given to the question of the balance between the various approximations.



The model is found to accurately reproduce well-determined experimental data for a few test systems. The model is also used to study solvation and photophysical processes for which experiment is presently unable to elucidate the molecular origin. Noteworthy results from these studies are: asymmetric solvation of the quadrupolar para-benzoquinone, interface specific effects to the spectra of indole at the air/water interface, polarization-repulsion couplings in the solvation of monatomic ions and significant dependence of the molecular structure of urea on the properties of the environment. (Less)
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author
supervisor
opponent
  • Professor Rossky, Peter J., University of Texas at Austin, USA
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Theoretical chemistry, quantum chemistry, Teoretisk kemi, kvantkemi, magnetisk resonans, Fysikalisk kemi, Physical chemistry, gränsskikt, Ytkemi, Surface and boundary layery chemistry, spektroskopi, egenskaper (elektriska, magnetiska och optiska), supraledare, Kondenserade materiens egenskaper:elektronstruktur, spectroscopy, relaxation, magnetic resonance, supraconductors, magnetic and optical properties, Kemi, Condensed matter:electronic structure, electrical, Solvent model, Solvochromatic shift, Chemistry, Solvent effects, Solvation, Intermolecular interactions, Quantum chemistry, Statistical mechanics
pages
196 pages
publisher
Avdelningen för teoretisk kemi
defense location
Sal B, Kemicentrum, Lunds universitet.
defense date
2008-01-11 10:15
ISBN
978-91-7422-175-6
language
English
LU publication?
yes
id
f80332c1-cd71-4a7f-81c2-a874663c2a4e (old id 599170)
date added to LUP
2007-11-13 08:44:58
date last changed
2016-09-19 08:45:03
@misc{f80332c1-cd71-4a7f-81c2-a874663c2a4e,
  abstract     = {A considerable part of chemistry in nature and industry, takes place in an environment of other molecules. Reactions, transitions, interactions or other chemical processes are almost always modified by the environment. These modifications or environment effects depend ultimately on the interactions between the molecules, the so called intermolecular interactions. The special case of effects induced by a solvent, such as water, are called solvent effects, and are widely studied and used to fine-tune properties of chemical processes.<br/><br>
<br/><br>
In this thesis, solvent effects are studied theoretically. Fundamental questions of how certain effects come about, that is their molecular origin, can be addressed through computer simulations. A new model with this purpose is formulated in the thesis. The model is developed from fundamental relations and well-established knowledge of intermolecular interactions, statistical mechanics and quantum mechanics. No experimental data are used as input into the model, rather the model proceeds from theoretical first principles. In the discussion of the model, special attention is given to the question of the balance between the various approximations.<br/><br>
<br/><br>
The model is found to accurately reproduce well-determined experimental data for a few test systems. The model is also used to study solvation and photophysical processes for which experiment is presently unable to elucidate the molecular origin. Noteworthy results from these studies are: asymmetric solvation of the quadrupolar para-benzoquinone, interface specific effects to the spectra of indole at the air/water interface, polarization-repulsion couplings in the solvation of monatomic ions and significant dependence of the molecular structure of urea on the properties of the environment.},
  author       = {Öhrn, Anders},
  isbn         = {978-91-7422-175-6},
  keyword      = {Theoretical chemistry,quantum chemistry,Teoretisk kemi,kvantkemi,magnetisk resonans,Fysikalisk kemi,Physical chemistry,gränsskikt,Ytkemi,Surface and boundary layery chemistry,spektroskopi,egenskaper (elektriska,magnetiska och optiska),supraledare,Kondenserade materiens egenskaper:elektronstruktur,spectroscopy,relaxation,magnetic resonance,supraconductors,magnetic and optical properties,Kemi,Condensed matter:electronic structure,electrical,Solvent model,Solvochromatic shift,Chemistry,Solvent effects,Solvation,Intermolecular interactions,Quantum chemistry,Statistical mechanics},
  language     = {eng},
  pages        = {196},
  publisher    = {ARRAY(0x9333878)},
  title        = {Development and Application of a First Principle Molecular Model for Solvent Effects},
  year         = {2008},
}