New 2,2′:4,4″:4′,4′″-quaterpyridyl transition metal complexes

Wolf, Paul de; Heath, Sarah L.; Thomas, Jim A.

doi:10.1016/s0020-1693(03)00370-0

Cited by 14 publications

(30 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some minor signals correspond to fragments and are typical for many metallo-supramolecular assemblies. The above-mentioned studies on quaterpyridine complexes [11,12] reported that the 2,2Ј-bipyridine site is the first one to complex to a given metal center. Afterwards, a second metal ion mediated the formation of the metallomacrocycles.…”

Section: Self-assembly Of Metallo-supramolecular Macrocyclesmentioning

confidence: 99%

“…This strategy is based on the formation of a kinetically inert complex of a ligand with the first metal ion followed by the formation of metallo-supramolecular macrocycles through coordination of the remaining binding sites to a kinetically labile metal ion. [11] In these quaterpyridine-based macrocycles, the inner cavities are rather small, even though extraction studies have shown small aromatic molecules to bind inside the cavities in water by the hydrophobic effect. [12] The aim of the present study is to extend the cavity size by inserting ethynylene spacers between the pyridine rings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multidentate Pyridyl‐Based Ligands in the Coordination‐Driven Self‐Assembly of Palladium Metallo‐Macrocycles

Brusilowskij¹,

Schalley²

2010

Eur J Org Chem

View full text Add to dashboard Cite

In the current study, a convenient way is presented to synthesize one ditopic and two tetratopic pyridine-based ligands, which are then used to construct metallo-supramolecular polygons. The tetratopic ligands offer two different metalbinding sites, one central 2,2Ј-bipyridine, which can act as a chelate ligand, and two separate pyridine rings, which mediate assembly formation. The three ligands differ with respect to their conformational flexibility. While a biphenyl core allows the ligand to adjust its conformation as needed, a bipyridine core strongly prefers a divergent arrangement of the additional pyridine binding sites, but can be fixed in a cisoid conformation by metal complexation to the bipyridine. Instead, a phenanthroline core already fixes the pyridinyl-

show abstract

Section: Self-assembly Of Metallo-supramolecular Macrocyclesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multidentate Pyridyl‐Based Ligands in the Coordination‐Driven Self‐Assembly of Palladium Metallo‐Macrocycles

Brusilowskij¹,

Schalley²

2010

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…The oxidation of complex 9 in acetonitrile was previously examined; [16] however, no oxidation was observed within the solvent window used. The oxidation of complex 9 in acetonitrile was previously examined; [16] however, no oxidation was observed within the solvent window used.…”

Section: Electrochemical Studiesmentioning

confidence: 99%

“…[15] With the aim of creating metallomacrocycles with tunable host-guest and photophysical properties, we are exploring the synthesis and properties of new metal complex building blocks. We have also synthesized the previously reported Re I complexes, [16] 8 and 9, so that more detailed photophysical studies and comparisons with the Ru II systems could be reported. In this study, we were particularly interested in exploring how the photophysical and electrochemical properties of the core MA C H T U N G T R E N N U N G (qtpy) unit could be tuned by varying the coordinated ancillary ligands or metal ion.…”

Section: Introductionmentioning

confidence: 99%

Tuning the Excited State of Photoactive Building Blocks for Metal‐Templated Self‐Assembly

Ahmad

Meijer

Thomas

2011

Chemistry An Asian Journal

View full text Add to dashboard Cite

The reaction of 2,2':4,4'':4',4'''-quaterpyridyl (qtpy), with d(6) ruthenium(II) (Ru(II) ), and rhenium(I) (Re(I) ) metal centers has been investigated. The pendant pyridyl groups on the products have also been methylated to produce a second series of complexes containing coordinated Meqtpy(2+). The absorption spectra of the complexes are dominated by intraligand and charge-transfer bands. The ruthenium(II) complexes display broad unstructured luminescence consistent with emission from a Ru(d)→diimine(π*) manifold in acetonitrile solutions. In aqueous solutions, their emissions are weaker and the lifetimes are shorter. This effect is particularly acute for complexes incorporating coordinated dipyridylpyrazine, dppz, ligands. Although the emission of the ruthenium(II) complexes containing Meqtpy(2+) is generally shorter than their qtpy analogs, it is notable that solvent-dependent effects are much less intense. The rhenium(I) complexes also display broad unstructured luminescence but, compared with the ruthenium(II) systems, they have a relatively short lifetime in acetonitrile. Electrochemical studies reveal that all of the Ru(II) complexes display chemically reversible metal-based oxidations. Re(I) complexes only display irreversible metal-based oxidations. In most cases, the reduction processes were not fully chemically reversible. The electrochemical and optical studies reveal that the nature of the lowest excited state of these complexes--particularly, the systems incorporating dppz--is highly dependent on the nature of the coordinated ligands. Calculations indicate that, although the excited state of most of the complexes is centered on the qtpy or Meqtpy(2+) ligands, the excited state of the complexes containing dppz ligands is switched away from the dppz by qtpy methylation. A crystallographic study on one of the dicationic ruthenium(II) structures reveals that it forms an inclusion complex with benzene.

show abstract

“…First, while the reactivity of coordinated cis-and trans-g 4 -diene are different, structurally their Ru-C distances are very similar that no major differences are observed. On the other hand, the redox potential can be used as a tool to pinpoint these minor differences and has been used very often in organometallic/inorganic chemistry as a characterization technique [12][13][14][15][16]. As can be seen, in general the trans-diene coordination appears to be more robust to oxidation than the cis one.…”

Section: Discussionmentioning

confidence: 99%