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Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions
Dissertation (MSc)--University of Pretoria, 2013.
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University of Pretoria
2014
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| _version_ | 1867613641492135936 |
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| access_status_str | Open Access |
| author2 | Cukrowski, Ignacy |
| author_browse | Cukrowski, Ignacy |
| author_facet | Cukrowski, Ignacy |
| collection | Thesis |
| dc_rights_str_mv | © 2013 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2013. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/40364 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:22.809Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/40364 Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions Cukrowski, Ignacy jurgensdl@gmail.com De Lange, Jurgens Hendrik Theoretical Chemistry 2,2′-Bipyridine H-clash QTAIM IQA NCI ETS-NOCV coordination chemistry UCTD Dissertation (MSc)--University of Pretoria, 2013. 2,2′-Bipyridine (BPy), one of the most widely used ligands in coordination chemistry, exists naturally in the s-trans conformation but must preorganize to the s-cis conformer in order to form chelating complexes. Lower stability of the s-cis conformer was mainly attributed to steric 3,3′-hydrogen clashes and nitrogen lone pair-lone pair interactions, but recent trends in the literature suggest that these clashes might be bonding interactions in similar molecules. These close contacts are also present in metal complexes with BPy and are often used as “steric repulsions” in order to explain trends in formation constants. In the present work we investigate the CH•••HC interaction in the free ligand as well as in ZnII(BPy)n(OH2)6-2n and NiII(BPy)n(OH2)6-2n complexes. We use multiple distinct advances in theoretical chemistry in order to arrive at a consistent and coherent model describing these interactions. The Quantum Theory of Atoms in Molecules (QTAIM) reveals the presence of an atomic interaction line (a bond path) for the CH•••HC interaction. Using the Interacting Quantum Atoms (IQA) energy decomposition scheme we show that the CH•••HC interaction is attractive and quantum mechanical in nature. The Extended Transition State coupled with Natural Orbitals for Chemical Valence (ETS-NOCV) energy decomposition scheme show favorable orbital mixing, and Non-Covalent Interaction (NCI) analysis reveals that no steric (Pauli) strain exists in the valence (overlap) regions of the interaction - electron density is concentrated rather than depleted in the bonding region. We also studied various other interactions, ranging from purely repulsive (N--N interaction in the s-cis conformer of BPy), purely electrostatic (CH•••N interaction in s-trans conformer of BPy), H-bonding (CH–N and CH–O bonds in complexes) to coordination bonds and covalent bonds. Using a comparative approach, we show the similarities and differences among the interactions, and conclude that the CH•••HC interaction cannot be classified as a “steric repulsion” - the interaction is similar in properties to every studied known bonding interaction and opposite in nature to the studied known repulsions. Finally, we suggest novel interpretations and understanding of the nature of intramolecular interactions and the field of theoretical chemistry, as well as representing the first work to combine and corroborate QTAIM, IQA, NCI and ETS-NOCV findings. gm2014 Chemistry unrestricted 2014-06-24T09:52:28Z 2014-06-24T09:52:28Z 2014-04-23 2013 Dissertation De Lange, JH 2013, Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/40364> E14/4/189/gm http://hdl.handle.net/2263/40364 en © 2013 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Theoretical Chemistry 2,2′-Bipyridine H-clash QTAIM IQA NCI ETS-NOCV coordination chemistry UCTD Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title | Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title_full | Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title_fullStr | Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title_full_unstemmed | Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title_short | Theoretical investigation of CH,HC contacts and other intramolecular interactions in 2,2′-Bipyridine and itscomplexes with metal ions |
| title_sort | theoretical investigation of ch hc contacts and other intramolecular interactions in 2 2 bipyridine and itscomplexes with metal ions |
| topic | Theoretical Chemistry 2,2′-Bipyridine H-clash QTAIM IQA NCI ETS-NOCV coordination chemistry UCTD |
| url | http://hdl.handle.net/2263/40364 |