FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2893033153> ?p ?o ?g. }

• W2893033153 abstract "This thesis is divided into two parts, the investigation of the electronic structure of cerium complexes paying special attention on the relevance of the cerium 4f orbitals in order to assign the oxidation state of cerium and the quality of density functional theory (DFT) computations and their consistency with experimental data in order to investigate the reliability of such calculations and their predictive credibility for reactions.In the first part, the electronic structure of the ground state of several cerium complexes, Ce(C8H8)2, Ce(C8H6)2, Cp2CeZ ( Z = CH2, CH-, NH, O, F+) as well as CH2CeF2 and OCeF2 were investigated. Using CASSCF computations including orbital rotations of the active orbitals, the underlying reason for the different interpretations of the cerium oxidation state (Ce(III) and Ce(IV)) of cerocene was found. By orbital rotation nearly pure cerium 4f and ligand pi orbitals were obtained for cerocene. The CASSCF wavefunction based on these localized orbitals was analyzed and a leading f1pi3 was obtained. Therefore, cerocene was classified as a Ce(III) compound. This result is in agreement to spectroscopic XANES data. Using the same computational technique, the electronic structure of all other cerium compounds was investigated. Similar to cerocene, nearly pure Ce 4f and ligand orbitals were obtained for Ce(C8H6)2, Cp2CeCH2, Cp2CeCH- and CH2CeF2 resulting in a leading f1pi1 or f1p1 configuration. Therefore these systems were classified as Ce(III) compounds. In contrast the complexes Cp2CeNH, Cp2CeO and OCeF2 should be described as mixed valent Ce(III)/Ce(IV) compounds, whereas the Cp2CeF+ complex can be categorized as a Ce(IV) compound.It can be shown that the most compact wavefunction, which correctly describes the influence of the Ce 4f orbitals can be obtained for all molecules, except cerocene, at the CASSCF(2,2) level. These compact wavefunctions based on localized orbitals were used to investigate the nature of the orbital interactions of the active orbitals. The results revealed that the 4f-pi orbital interaction of Ce(C8H6)2 as well as the 4f-p orbital interaction of CH2CeCp2, CH-CeCp2 and CH2CeF2 of the Ce-CH2 or Ce-CH bonds can be classified as covalent interactions. The mixed valent systems revealed an increased ionic character of the active orbital interactions for the Ce-NH and Ce-O bonds, whereas the Ce-F bond can be clearly described as ionic. These results are in a good agreement to the assigned oxidation states.In the second part of this thesis, the quality and reliability of DFT computations of reactionscompared to experimental results was investigated. The energies of the starting materials, the products as well as the transition states of several iodine catalyzed reactions were computed using various DFT methods. The results revealed that experimental outcomes (reaction time and product yields) can not be computed reliably for the whole set of investigated reactions. Additionally, it revealed that modern and older functionals possess the same predictive credibility. Nevertheless it was shown that all experimental outcomes of the reactions between methyl acrylate and aniline derivatives were reproduced by DFT methods. Therefore a reliable reaction prediction using DFT methods is not generally performable, but based on experimental results, DFT computations can predict reaction trends of very similar systems correctly. These correct predictions were obtained by all used functionals, which emphasizes that for a specific application modern and older functionals might possess the same quality." @default.
• W2893033153 created "2018-10-05" @default.
• W2893033153 creator A5007792017 @default.
• W2893033153 date "2018-03-15" @default.
• W2893033153 modified "2023-09-24" @default.
• W2893033153 title "Interpretation of ab initio Calculations of Cerium Compounds and Predictive Power of Density Functional Theory Calculations for Iodine Catalysis" @default.
• W2893033153 hasPublicationYear "2018" @default.
• W2893033153 type Work @default.
• W2893033153 sameAs 2893033153 @default.
• W2893033153 citedByCount "0" @default.
• W2893033153 crossrefType "dissertation" @default.
• W2893033153 hasAuthorship W2893033153A5007792017 @default.
• W2893033153 hasConcept C121332964 @default.
• W2893033153 hasConcept C139358910 @default.
• W2893033153 hasConcept C147120987 @default.
• W2893033153 hasConcept C147597530 @default.
• W2893033153 hasConcept C147789679 @default.
• W2893033153 hasConcept C152365726 @default.
• W2893033153 hasConcept C161790260 @default.
• W2893033153 hasConcept C178790620 @default.
• W2893033153 hasConcept C179104552 @default.
• W2893033153 hasConcept C185592680 @default.
• W2893033153 hasConcept C189394030 @default.
• W2893033153 hasConcept C2778591166 @default.
• W2893033153 hasConcept C32909587 @default.
• W2893033153 hasConcept C523597863 @default.
• W2893033153 hasConcept C55493867 @default.
• W2893033153 hasConcept C62520636 @default.
• W2893033153 hasConcept C86025842 @default.
• W2893033153 hasConceptScore W2893033153C121332964 @default.
• W2893033153 hasConceptScore W2893033153C139358910 @default.
• W2893033153 hasConceptScore W2893033153C147120987 @default.
• W2893033153 hasConceptScore W2893033153C147597530 @default.
• W2893033153 hasConceptScore W2893033153C147789679 @default.
• W2893033153 hasConceptScore W2893033153C152365726 @default.
• W2893033153 hasConceptScore W2893033153C161790260 @default.
• W2893033153 hasConceptScore W2893033153C178790620 @default.
• W2893033153 hasConceptScore W2893033153C179104552 @default.
• W2893033153 hasConceptScore W2893033153C185592680 @default.
• W2893033153 hasConceptScore W2893033153C189394030 @default.
• W2893033153 hasConceptScore W2893033153C2778591166 @default.
• W2893033153 hasConceptScore W2893033153C32909587 @default.
• W2893033153 hasConceptScore W2893033153C523597863 @default.
• W2893033153 hasConceptScore W2893033153C55493867 @default.
• W2893033153 hasConceptScore W2893033153C62520636 @default.
• W2893033153 hasConceptScore W2893033153C86025842 @default.
• W2893033153 hasLocation W28930331531 @default.
• W2893033153 hasOpenAccess W2893033153 @default.
• W2893033153 hasPrimaryLocation W28930331531 @default.
• W2893033153 hasRelatedWork W1971841978 @default.
• W2893033153 hasRelatedWork W1987258691 @default.
• W2893033153 hasRelatedWork W1998847655 @default.
• W2893033153 hasRelatedWork W2005219306 @default.
• W2893033153 hasRelatedWork W2016126749 @default.
• W2893033153 hasRelatedWork W2021716101 @default.
• W2893033153 hasRelatedWork W2071716604 @default.
• W2893033153 hasRelatedWork W2088905169 @default.
• W2893033153 hasRelatedWork W2094593502 @default.
• W2893033153 hasRelatedWork W2099257022 @default.
• W2893033153 hasRelatedWork W2104749956 @default.
• W2893033153 hasRelatedWork W2136784198 @default.
• W2893033153 hasRelatedWork W2233623116 @default.
• W2893033153 hasRelatedWork W2327147244 @default.
• W2893033153 hasRelatedWork W2463732199 @default.
• W2893033153 hasRelatedWork W2468945140 @default.
• W2893033153 hasRelatedWork W2591602612 @default.
• W2893033153 hasRelatedWork W2597499018 @default.
• W2893033153 hasRelatedWork W2909065745 @default.
• W2893033153 hasRelatedWork W75827520 @default.
• W2893033153 isParatext "false" @default.
• W2893033153 isRetracted "false" @default.
• W2893033153 magId "2893033153" @default.
• W2893033153 workType "dissertation" @default.