1:1 Metal complexes of 2-(2′-pyridyl)quinoxaline, a ligand unexpectedly formed by the reaction between 2-acetylpyridine and 1,2-phenylenediamine

Kasselouri, Spyridoula; Garoufis, Achilleas; Katehanakis, Agathopous; Kalkanis, George; Perlepes, Spyros P.; Hadjiliadis, Nick

doi:10.1016/s0020-1693(00)90718-7

Cited by 79 publications

(30 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2-(2 0 -pyridyl)quinoxaline [31,34], and Pt(pq)Cl 2 [35] were prepared according to the literature procedures. All reactions and manipulations were conducted under a pure argon atmosphere using standard Schlenk techniques.…”

Section: Methodsmentioning

confidence: 99%

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Mitsopoulou

Dagas

Makedonas

2008

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Mitsopoulou

Dagas

Makedonas

2008

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

“…[12] The bridging ligand dpq was supplied by Dr Laurence Kelso and was prepared according to the literature methodology. [70] General: 1D and 2D 1 H NMR spectra were collected on a Varian Mercury 300 MHz spectrometer. 1 H NMR assignments were performed with the assistance of COSY experiments to identify each pyridine ring system.…”

Section: Methodsmentioning

confidence: 99%

Probing the Transition between the Localised (Class II) and Localised‐to‐Delocalised (Class II–III) Regimes by Using Intervalence Charge‐Transfer Solvatochromism in a Series of Mixed‐Valence Dinuclear Ruthenium Complexes

D’Alessandro

Topley

Davies

et al. 2006

Chemistry A European J

View full text Add to dashboard Cite

Intervalence charge-transfer (IVCT) solvatochromism studies on the diastereoisomeric forms of [{Ru(bpy)(2)}(2)(mu-BL)](5+) (bpy=2,2'-bipyridine; BL=a series of di-bidentate polypyridyl bridging ligands) reveal that the solvent dependencies of the IVCT transitions decrease as the "tail" of the bridging ligand is extended, and the extent of delocalisation increases. Utilising a classical theoretical approach for the analysis of the intervalence charge-transfer (IVCT) solvatochromism data, the subtle and systematic variation in the electronic properties of the bridging ligands can be correlated with the shift between the localised (class II) and localised-to-delocalised (class II-III) regimes. The investigation of the diastereoisomeric forms of two series of complexes incorporating analogous structurally rigid (fused) and nonrigid (unfused) bridging ligands demonstrates that the differences in the IVCT characteristics of the diastereoisomers of a given complex are accentuated in the latter case, due to a stereochemically induced redox asymmetry contribution. The marked dependence of the IVCT transitions on the stereochemical identity of the complexes provides a quantitative measure of the fundamental contributions of the reorganisational energy and redox asymmetry to the intramolecular electron-transfer barrier at the molecular level.

show abstract

“…The complexes cis-[RuCl 2 (bpy) 2 ] [31] and Λ-and ∆-[Ru(bpy) 2 (py) 2 ]A·12H 2 O (where Α ϭ O,OЈ-dibenzoyltartaric acid), [32,33] and the ligand 2-(2Ј-pyridyl)quinoxaline (pqx) were synthesised according to literature procedures. [34] Instrumentation: Elemental analyses for C, H and N were performed using a CarloϪErba 1108 apparatus. CD spectra were recorded on a Jasco J-720 spectropolarimeter.…”

Section: Methodsmentioning

confidence: 99%

NMR Evidence for Major Groove Binding of Both Λ‐ and Δ‐[Ru(bpy)₂(pqx)](PF₆)₂ to the Oligonucleotide d(CGCGAATTCGCG)₂

2004

Self Cite

View full text Add to dashboard Cite

The enantiomeric complexes Λ-and ∆-[Ru(bpy) 2 (pqx)](PF 6 ) 2 [pqx = 2-(2Ј-pyridyl)quinoxaline] were synthesized and characterized by various spectroscopic techniques. Their binding properties to the oligonucleotide duplex d(CGCGAATTCGCG) 2 were subsequently studied by NMR spectroscopy. 1D and 2D NMR techniques provided evidence for major-groove binding of both enantiomers with the oligonucleotide. The ∆-[Ru(bpy) 2 (pqx)](PF 6 ) 2 enantiomer binds IndroductionThe binding properties of transition metal tris-chelate complexes with DNA have been extensively studied in recent years. [1,2] One of the pioneering works was the report by Barton et al. pointing out the remarkable difference in the binding strength of the enantiomers of [Zn(phen) 3 ] 2ϩ with DNA.[3] The interactions between CT-DNA and the enantiomeric ruthenium complexes Λ-and ∆-[Ru(phen) 3 ] 2ϩ have been studied by several methods, with controversial conclusions. Several studies led to the conclusion that the ∆-isomer either intercalates between the base pairs, [4Ϫ7] or is partially inserted, [8Ϫ10] or it binds to DNA in various ways [11,12] (e.g. in the major [8,10] or in the minor groove [13,14] ). On the other hand Λ-[Ru(phen) 3 ] 2ϩ binds to DNA either by electrostatic forces, [4,5] or surface-bound interactions, [6,12] and with weak binding in the minor [13,14] or the major groove. [8,10] 2,2Ј-Bipyridine has been used as a ligand less often than 1,10-phenanthroline in tris-chelate complexes of Ru II in studies of interactions with DNA due to the lower affinity of this ligand to bind to the DNA helix. Based on photophysical results, it has been suggested that ation or electrostatic interactions. [4,5,15] It has also been reported that no enantiomeric discrimination is apparent between the binding of Λ-and ∆-[Ru(bpy) 3 ] 2ϩ with DNA.[16]The interaction of the mixed-ligand complex [Ru(bpy) 2 (phen)] 2ϩ with DNA has been studied by linear dichroism spectroscopy with the aim of investigating the role of each ligand involved in the complex. The results indicate that the complex shows a similar binding geometry to [Ru(phen) 3 ] 2ϩ in which one phen ligand faces the DNA base pairs, almost as if it were intercalated nearly parallel to them.[9] A similar mixed-ligand complex, [Ru(bpy) 2 (ppz)] 2ϩ (ppz ϭ 4,7-phenanthrolino [6,5-b]pyrazine, a non-classical intercalative ligand), which is longer than phen by a sixmembered fused ring, shows that both Λ-and ∆-enantiomers bind in the major groove of DNA by partial intercalation of the ppz ligand. The bpy ligands are not capable of inducing intercalation and the enantioselectivity is maintained by the different interactions of the ∆-and Λ-enantiomers with the DNA major groove. [17] In an attempt to contribute to the better understanding of how these mixedligand complexes bind to DNA, we have synthesized, characterized and studied the binding properties of the enantiomeric complexes Λ-and ∆-[Ru(bpy) 2 (pqx)] 2ϩ [pqx ϭ 2-(2Ј-pyridyl)quinoxaline], to the oligonucleotide duplex d(5Ј-CGCGAATTCGCG-3Ј) 2 mainly by NMR...

show abstract

1:1 Metal complexes of 2-(2′-pyridyl)quinoxaline, a ligand unexpectedly formed by the reaction between 2-acetylpyridine and 1,2-phenylenediamine

Cited by 79 publications

References 24 publications

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Probing the Transition between the Localised (Class II) and Localised‐to‐Delocalised (Class II–III) Regimes by Using Intervalence Charge‐Transfer Solvatochromism in a Series of Mixed‐Valence Dinuclear Ruthenium Complexes

NMR Evidence for Major Groove Binding of Both Λ‐ and Δ‐[Ru(bpy)₂(pqx)](PF₆)₂ to the Oligonucleotide d(CGCGAATTCGCG)₂

Contact Info

Product

Resources

About

1:1 Metal complexes of 2-(2′-pyridyl)quinoxaline, a ligand unexpectedly formed by the reaction between 2-acetylpyridine and 1,2-phenylenediamine

Cited by 79 publications

References 24 publications

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Synthesis, characterization, DFT studies and DNA binding of mixed platinum (II) complexes containing quinoxaline and 1,2-dithiolate ligands

Probing the Transition between the Localised (Class II) and Localised‐to‐Delocalised (Class II–III) Regimes by Using Intervalence Charge‐Transfer Solvatochromism in a Series of Mixed‐Valence Dinuclear Ruthenium Complexes

NMR Evidence for Major Groove Binding of Both Λ‐ and Δ‐[Ru(bpy)2(pqx)](PF6)2 to the Oligonucleotide d(CGCGAATTCGCG)2

Contact Info

Product

Resources

About

NMR Evidence for Major Groove Binding of Both Λ‐ and Δ‐[Ru(bpy)₂(pqx)](PF₆)₂ to the Oligonucleotide d(CGCGAATTCGCG)₂