Evaluating π-π stacking effects in macrocyclic transition metal complexes using EPR techniques

Evaluating π-π stacking effects in macrocyclic transition metal complexes using EPR techniques The HYSCORE spectra for two different macrocyclic transition metal complexes, namely cobalt tetraphenylporphyrin (CoTPP) and a copper Salen derivative ([Cu(1)]), were examined in relation to their interactions with pyridine (Py) and methylbenzyl amine (MBA), respectively. In both cases weak hyperfine interactions were detected by HYSCORE, but the origin of these interactions was found to originate from completely different effects. In the CoTPPpy adduct, with axial coordination of the substrate (pyridine) to the metal centre, weak couplings from the pyrrole nitrogens of a neighbouring porphyrin complex were identified, and confirmed through a series of isotopic labelling and dilution experiments. This result represents the first ever identification by HYSCORE of π-π interactions between such porphyrin complexes in solution. In the [Cu(1)]MBA adduct, again with axial coordination of the substrate (MBA) to the copper centre, weak couplings were also identified in the HYSCORE spectra, which could easily be misinterpreted as arising from intermolecular interactions between adjacent ligands. However, the origin of these couplings was clearly demonstrated to arise from intramolecular 13C-ligand interactions. These results demonstrate not only the sensitivity of the HYSCORE technique for detection of weak inter- and intra-molecular interactions in macrocyclic transition metal complexes, but additionally the need to consider dilution effects in the spectral assignments. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Research on Chemical Intermediates Springer Journals

Evaluating π-π stacking effects in macrocyclic transition metal complexes using EPR techniques

Loading next page...
 
/lp/springer_journal/evaluating-stacking-effects-in-macrocyclic-transition-metal-complexes-dpViNlGNX4
Publisher
Springer Journals
Copyright
Copyright © 2007 by VSP
Subject
Chemistry; Catalysis; Physical Chemistry; Inorganic Chemistry
ISSN
0922-6168
eISSN
1568-5675
D.O.I.
10.1163/156856707782169318
Publisher site
See Article on Publisher Site

Abstract

The HYSCORE spectra for two different macrocyclic transition metal complexes, namely cobalt tetraphenylporphyrin (CoTPP) and a copper Salen derivative ([Cu(1)]), were examined in relation to their interactions with pyridine (Py) and methylbenzyl amine (MBA), respectively. In both cases weak hyperfine interactions were detected by HYSCORE, but the origin of these interactions was found to originate from completely different effects. In the CoTPPpy adduct, with axial coordination of the substrate (pyridine) to the metal centre, weak couplings from the pyrrole nitrogens of a neighbouring porphyrin complex were identified, and confirmed through a series of isotopic labelling and dilution experiments. This result represents the first ever identification by HYSCORE of π-π interactions between such porphyrin complexes in solution. In the [Cu(1)]MBA adduct, again with axial coordination of the substrate (MBA) to the copper centre, weak couplings were also identified in the HYSCORE spectra, which could easily be misinterpreted as arising from intermolecular interactions between adjacent ligands. However, the origin of these couplings was clearly demonstrated to arise from intramolecular 13C-ligand interactions. These results demonstrate not only the sensitivity of the HYSCORE technique for detection of weak inter- and intra-molecular interactions in macrocyclic transition metal complexes, but additionally the need to consider dilution effects in the spectral assignments.

Journal

Research on Chemical IntermediatesSpringer Journals

Published: Jan 1, 2007

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off