Sökning: "B3LYP"

Visar resultat 1 - 5 av 31 avhandlingar innehållade ordet B3LYP.

1. 1. Photophysical Properties of Organic and Organometallic molecules

   Författare :Oscar Rubio Pons; KTH; []
   Nyckelord :molecule; two-photon absorption; singlet-triplet. spin-orbit; CASSCF; emission; phosphorescence; DFT; B3LYP;

   Sammanfattning : Highly correlated quantum chemical methods have been appliedto study the photophysical properties of substituted benzenes.With the inclusion of spin-orbit coupling, the phosphorescencesof these molecules have been calculated usingMulti-CongurationalSelf- Consistent Field (MCSCF) quadraticresponse theory. LÄS MER

3. 2. Quantum Chemical Cluster Modeling of Enzymatic Reactions

   Författare :Rongzhen Liao; Fahmi Himo; Robert Deeth; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cluster approach; density functional theory; B3LYP; enzyme; mechanism; dinuclear; trinuclear; zinc; tungsten; hydrolysis; decarboxylation; formaldehyde oxidation; hydration; methyl transfer; Quantum chemistry; Kvantkemi; organisk kemi; Organic Chemistry;

   Sammanfattning : The Quantum chemical cluster approach has been shown to be quite powerful and efficient in the modeling of enzyme active sites and reaction mechanisms. In this thesis, the reaction mechanisms of several enzymes have been investigated using the hybrid density functional B3LYP. LÄS MER

4. 3. Theoretical studies of blue copper proteins

   Författare :Mats H M Olsson; Beräkningskemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; metal-thiolate bonds; axial ligation; electron transfer proteins; reduction potential; reorganisation energy; Cu II ; Cu I ; strain; Induced-rack theory; Entatic state theory; cytochrome c oxidase; CuA; nitrite reductase; azurin; Blue copper proteins; plastocyanin; B3LYP; CASPT2; Soil Science; agricultural hydrology; Lantbrukshydrologi; marklära;

   Sammanfattning : In this thesis, a critical investigation is presented about the role of mechanical strain for the electron-transfer properties of the blue copper proteins. It has been found that the structure of a realistic model complex of the oxidised blue-copper active site, optimised in vacuum with the B3LYP method, has the same trigonal cupric geometry as in the protein. LÄS MER

5. 4. Quantum Chemical Modeling of Asymmetric Enzymatic Reactions

   Författare :Maria E. S. Lind; Fahmi Professor; Rajeev Prabhakar; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biocatalysis; enantioselectivity; density functional theory; B3LYP; enzyme; hydrolysis; decarboxylation; Organic Chemistry; organisk kemi;

   Sammanfattning : Computational methods are very useful tools in the study of enzymatic reactions, as they can provide a detailed understanding of reaction mechanisms and the sources of various selectivities. In this thesis, density functional theory has been employed to examine four different enzymes of potential importance for biocatalytic applications. LÄS MER

7. 5. Quantum Chemical Studies of Enzymatic Reaction Mechanisms

   Författare :Bianca Manta; Fahmi Himo; Lubomir Rulisek; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; B3LYP; enzyme; cluster approach; mechanism; zinc; manganese; cytosine deaminase; ω-transaminase; dinitrogenase reductase-activating glycohydrolase; dual substrate recognition; organisk kemi; Organic Chemistry;

   Sammanfattning : Computer modeling of enzymes is a valuable complement to experiments. Quantum chemical studies of enzymatic reactions can provide a detailed description of the reaction mechanism and elucidate the roles of various residues in the active site. LÄS MER