Isomerism in copper(I)-induced folding of homoditopic macrocyclic ligands with bis(dithiadiimine) donor sets
The structural properties of the dicopper(I) compounds of the two large macrocyclic Schiff base ligands para-222 and meta-222 with two dithiadiimine coordination sites, where the two sites are linked by two para- or two meta-xylylene spacer groups and all bridges between the donors of each site are...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 February 1999
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| In: |
European journal of inorganic chemistry
Year: 1999, Issue: 3, Pages: 509-515 |
| ISSN: | 1099-0682 |
| DOI: | 10.1002/(SICI)1099-0682(199903)1999:3<509::AID-EJIC509>3.0.CO;2-9 |
| Online Access: | Verlag, Pay-per-use, Volltext: http://dx.doi.org/10.1002/(SICI)1099-0682(199903)1999:3<509::AID-EJIC509>3.0.CO;2-9 Verlag, Pay-per-use, Volltext: http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1099-0682(199903)1999:3<509::AID-EJIC509>3.0.CO;2-9/abstract 
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| Author Notes: | Peter Comba and Andreas Kühner |
| Summary: | The structural properties of the dicopper(I) compounds of the two large macrocyclic Schiff base ligands para-222 and meta-222 with two dithiadiimine coordination sites, where the two sites are linked by two para- or two meta-xylylene spacer groups and all bridges between the donors of each site are ethylene groups (32- and 30-membered macrocycles for the para- or meta-xylylen-bridged para-222 and meta-222 species, respectively) are studied, in solution and by computer modeling. Solid-state structural data have been reported elsewhere. The coordination of the 32-membered macrocycle para-222 to two copper(I) centers leads to a helical figure-of-eight-shaped structure. Two diastereomeric pairs of enantiomers have been observed for this type of compound in solution. The crystallized form is more stable than the second isomer by approximately 6-10 kJ/mol (solution-NMR spectroscopy and force-field calculations). Both experimentally detected isomers are more than 15 kJ/mol more stable than the other five possible configurations (force-field calculations). For the meta-222 macrocycle (30-membered ring) an achiral structure has been observed in the solid while two of the 21 possible isomers have been detected in solution (3:1, NMR spectroscopy). The computed structures and isomer distributions (force-field calculations) are compared with the solid-state structures and with observed isomer distributions from NMR experiments, and dynamic processes are analyzed in detail. |
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| Item Description: | Gesehen am 13.03.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1099-0682 |
| DOI: | 10.1002/(SICI)1099-0682(199903)1999:3<509::AID-EJIC509>3.0.CO;2-9 |