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Computational study of the boron-nitrogen dative bond
Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2007.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2008
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| _version_ | 1867614136718852096 |
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| access_status_str | Open Access |
| author | Zhao, Hailiang |
| author2 | Dillen, J. |
| author_browse | Dillen, J. Zhao, Hailiang |
| author_facet | Dillen, J. Zhao, Hailiang |
| author_sort | Zhao, Hailiang |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2007. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2846 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:47:15.075Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/2846 Computational study of the boron-nitrogen dative bond Zhao, Hailiang Dillen, J. Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science. Boron compounds Nitrogen compounds Electrostatic effect Solid state Data processing in chemistry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2007. In this study, ten selected boron-nitrogen compounds and three borane carbonyl complexes were investigated by a number of computational methods. It is well known that the B-N dative bond is shorter in the solid state than in the gas phase. The B-CO distance, on the other hand, displays the opposite effect. Quantum mechanical techniques at the Hartree-Fock, Møller-Plesset second-order and Density Functional Theory level were used to calculate the geometries of the isolated molecules and to compare them with those found in molecular clusters built to model the solid state. It was found that calculated geometries were very sensitive to the choice of the basis set. The effects of dipole-dipole interactions were further investigated by applying an external electric field with varying strength to isolated molecules, and by replacing the central molecule in a cluster with a different compound. The B-N bond was found to respond much more to the applied field than the B-CO bond. An effort was made to correlate the lengthening or shortening of the dative bond to the strength of the crystal field, the latter being calculated classically from point charges. Unfortunately, large differences were noted between the charges calculated with common methods like Mulliken or Merz-Kollman-Singh. Furthermore, an analysis of 67 crystal structures taken from the Cambridge Structural Database did not reveal a correlation between the length of the B-N bond and the crystal field calculated with Charge Equilibration charges. Finally, a valence force field was developed for H3N-BH3. It was shown that a much better fit of the vibrational spectrum can be obtained if the B-N stretching mode is assigned to the 603 cm-1 band rather than the peak observed at 968 cm-1. 2008-09-02T08:53:31Z 2010-06-01T08:59:52Z 2008-09-02T08:53:31Z 2010-06-01T08:59:52Z 2008-12 Thesis http://hdl.handle.net/10019.1/2846 en University of Stellenbosch application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Boron compounds Nitrogen compounds Electrostatic effect Solid state Data processing in chemistry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Zhao, Hailiang Computational study of the boron-nitrogen dative bond |
| title | Computational study of the boron-nitrogen dative bond |
| title_full | Computational study of the boron-nitrogen dative bond |
| title_fullStr | Computational study of the boron-nitrogen dative bond |
| title_full_unstemmed | Computational study of the boron-nitrogen dative bond |
| title_short | Computational study of the boron-nitrogen dative bond |
| title_sort | computational study of the boron nitrogen dative bond |
| topic | Boron compounds Nitrogen compounds Electrostatic effect Solid state Data processing in chemistry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/2846 |
| work_keys_str_mv | AT zhaohailiang computationalstudyoftheboronnitrogendativebond |