Bispidine Copper(II) compounds: effects of the rigid ligand backbone
Approximative density-functional theory calculations indicate that the tetradentate ligand L (L = 2,4-bis-(2-pyridyl)-3,7-diaza-[3.3.1]-bicyclononane) enforces an unusual and strong binding of a co-ligand (substrate) to a copper(II) center. The co-ligand in [Cu(L)(Cl)]+ completes a square-pyramidal...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
08/30/2001
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| In: |
Inorganic chemistry
Year: 2001, Volume: 40, Issue: 20, Pages: 5206-5209 |
| ISSN: | 1520-510X |
| DOI: | 10.1021/ic010200r |
| Online Access: | Verlag, Pay-per-use, Volltext: http://dx.doi.org/10.1021/ic010200r Verlag, Pay-per-use, Volltext: https://doi.org/10.1021/ic010200r 
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| Author Notes: | Peter Comba and Achim Lienke |
| Summary: | Approximative density-functional theory calculations indicate that the tetradentate ligand L (L = 2,4-bis-(2-pyridyl)-3,7-diaza-[3.3.1]-bicyclononane) enforces an unusual and strong binding of a co-ligand (substrate) to a copper(II) center. The co-ligand in [Cu(L)(Cl)]+ completes a square-pyramidal coordination around copper(II) and binds in the equatorial plane rather than on the apical position. This configuration is a stable geometric isomer for the model complex [Cu(NH3)2(imine)2(Cl)]+, but it is disfavored by approximately 10 kJ mol-1 and not commonly observed for CuN4 chromophores with a monodentate co-ligand. The equatorial coordination increases the bond energy of the copper(II)−chloride bond by approximately 80 kJ mol-1, and similar results are expected for other copper(II)−L-substrate complexes, some of which show strong catalytic activity or unusual stability. Despite the enforced configuration, L does not impose significant steric strain on the copper(II) center but is well preorganized for the Jahn−Teller labile ion in this unusual geometry. The preorganization extends to the orientation of the pyridine donors (torsion angle around the copper−pyridine bond), and this seems to be of importance in the reactivity of the copper−L complexes and their derivatives. |
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| Item Description: | Gesehen am 07.03.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1520-510X |
| DOI: | 10.1021/ic010200r |