Sökning: "hyperfine coupling constant"

Hittade 5 avhandlingar innehållade orden hyperfine coupling constant.

1. 1. Magnetic Resonance Parameters of Radicals Studied by Density Functional Theory Methods

   Författare :Lyudmyla Telyatnyk; KTH; []
   Nyckelord :electronic g-tensor; hyperfine coupling constant; nuclear shielding tensor; spin restricted DFT; restricted-unrestricted appoach;

   Sammanfattning : The recent state of art in the magnetic resonance area putsforward the electron paramagnetic resonance, EPR, and nuclearmagnetic resonance, NMR, experiments on prominent positions forinvestigations of molecular and electronic structure. A mostdifficult aspect of such experiments is usually the properinterpretation of data obtained from high-resolution spectra,that, however, at the same time opens a great challenge forpure theoretical methods to interpret the spectral features. LÄS MER

3. 2. Quantum Chemical Studies of Radical Cation Rearrangement, Radical Carbonylation, and Homolytic Substitution Reactions

   Författare :Daniel Norberg; Nessima Salhi-Benachenhou; Sten Lunell; Tim Clark; Uppsala universitet; []
   Nyckelord :Quantum chemistry; quantum chemistry; coupled-cluster; density functional theory; meta-GGA; reaction mechanism; potential energy surface; isomerization; fragmentation; dissociation; condensation; addition; SH2; hydrogen abstraction; iodine atom transfer; complex; weakly interacting system; hyperfine coupling constant; Kvantkemi;

   Sammanfattning : Quantum chemical calculations have been performed to investigate radical cation rearrangement, radical carbonylation, and homolytic substitution reactions of organic molecules. The rearrangement of the bicyclopropylidiene radical cation to the tetramethyleneethane radical cation is predicted to proceed with stepwise disrotatory opening of the two rings. LÄS MER

4. 3. Density functional studies of EPR and NMR parameters of paramagnetic systems

   Författare :Lyudmyla G. Telyatnyk; Olav Vahtras; Martin Kaupp; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-restricted DFT; restricted-unrestricted approach; EPR spin Hamiltonian parameters; NMR spin Hamiltonian parameters; Bioorganic chemistry; Bioorganisk kemi;

   Sammanfattning : Experimental methods based on the magnetic resonance phenomenon belong to the most widely used experimental techniques for investigations of molecular and electronic structure. The difficulty with such experiments, usually a proper interpretation of data obtained from high-resolution spectra, opens new challenges for pure theoretical methods. LÄS MER

5. 4. Theoretical Studies on Magnetic and Photochemical Properties of Organic Molecules

   Författare :Xing Chen; Olav Vahtras; Zilvinas Rinkevicius; Ian Carmichael; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The present thesis is concerned with the theoretical studies on magnetic and photochemical properties of organic molecules. The ab initio and first principles theories were employed to investigate the vibrational effects on the isotropic hyperfine coupling constant (HFCC) known as the critical parameter in electron paramagnetic resonance spectrum, the theoretical simulations of the vibronically resolved molecular spectra, the photo-induced reaction mechanism of α-santonin and the spin-forbidden reaction of triplet-state dioxygen with cofactor-free enzyme. LÄS MER

7. 5. Studies of Local Interactions between and within Proteins using Site-Directed Labeling Techniques

   Författare :Rikard Owenius; Lawrence J. Berliner; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Proteins are essential participants in virtually all cellular processes. The key to the understanding of the function of a certain protein is a detailed knowledge about its atomic three-dimensional structure. LÄS MER