C7430 Delocalization of Sigma Electrons in Molecules, Exemplified on Oligosilanes

Faculty of Science
Autumn 2004
Extent and Intensity
2/0. (fasci plus compl plus > 4). Recommended Type of Completion: k (colloquium). Other types of completion: zk (examination).
Teacher(s)
prof. Josef Michl (lecturer), doc. RNDr. Ctibor Mazal, CSc. (deputy)
doc. RNDr. Ctibor Mazal, CSc. (assistant)
prof. RNDr. Milan Potáček, CSc. (alternate examiner)
Guaranteed by
prof. RNDr. Milan Potáček, CSc.
Chemistry Section – Faculty of Science
Contact Person: prof. RNDr. Milan Potáček, CSc.
Course Enrolment Limitations
The course is also offered to the students of the fields other than those the course is directly associated with.
fields of study / plans the course is directly associated with
there are 13 fields of study the course is directly associated with, display
Syllabus
  • Lectures 1 and 2 - Introduction Simple models of electronic structure of saturated molecules. When is a single Lewis structure inadequate. Motivation for an examination of sigma electron delocalization. MO theory. Natural hybrid orbitals. The Hückel approximation, sigma conjugation, sigma hyperconjugation, and sigma homoconjugation. Reasons for choosing oligosilanes for a detailed study. Lectures 3 and 4 - General Background The Sandorfy C and H models. The ladder C and H models. What do delocalized sigma MOs look like? Model parameterization and comparison with ab initio Hartree-Fock orbital energies and observed ionization potentials. Lectures 5 and 6 - Chain Length Effects in Electronic Spectra Electronic states of a single Si-Si bond. Electronic states of concatenated Si-Si bonds: oligosilane chains, planar and helical. Extrapolation to infinite chains. Lectures 7 and 8 - Conformational Effects in Electronic Spectra Favored conformations of linear chains. Electronic states as a function of the skeletal dihedral angle in tetrasilane; correlation diagrams. Electronic states of the conformers of higher oligosilanes. Thermochromism of oligosilanes and polysilanes. Interruption of delocalization - what causes it? Lectures 9 and 10 - Excitation Localization vs. Delocalization, Summary Fluorescence from localized and delocalized excited states (excitons). Relation to exciton - phonon coupling in solids. What have we learned and can we apply it elsewhere (diastereoselection)?
Assessment methods (in Czech)
Výuka bude probíhat blokově v době návštěvy Prof. Josefa Michla na katedře organické chemie: 6.10.03 13 - 17 hod - zasedačka děkanátu 7.10.03 13 - 17 hod - zasedačka děkanátu 8.10.03 8 - 12 hod - zasedačka děkanátu Zkouška či kolokvium bude po dohodě s Doc. dr. C. Mazalem, CSc
Language of instruction
English
Further Comments
The course can also be completed outside the examination period.
The course is taught only once.
The course is taught: in blocks.
The course is also listed under the following terms Autumn 2007 - for the purpose of the accreditation, Autumn 2003, Autumn 2005, Autumn 2006, Autumn 2007.
  • Enrolment Statistics (Autumn 2004, recent)
  • Permalink: https://is.muni.cz/course/sci/autumn2004/C7430