Electrochemical characterization of a self-assembled double strand copper complex composed of three Cu+ and two ligands containing bis(bipyridine) bithiophene

Greenwald, Moshe; Eassa, Majed; Katz, Eugenii; Willner, Itamar; Cohen, Yoram

doi:10.1016/s0022-0728(97)00060-0

Cited by 11 publications

(14 citation statements)

References 24 publications

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“…2,10-Phenanthroline is a chelating ligand that possesses coordination features that are very similar to those of 2,2‘-bipyridine . Ligand strands 8 are analogous to the tris(bipyridine) derivative 7b with at least one bipyridine unit substituted by phenanthroline (or in 8d bithiophene). − All of ligands 8 form trinuclear double-stranded helicates [Cu 3 8 2 ] 3+ with copper(I) ions. Complex [Cu 3 8a 2 ] 3+ could be characterized by X-ray structural analysis .…”

Section: Linear Oligonitrogen Donors As Ligands For Double- and Tripl...mentioning

confidence: 99%

“Let's Twist Again”Double-Stranded, Triple-Stranded, and Circular Helicates

2001

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Section: Linear Oligonitrogen Donors As Ligands For Double- and Tripl...mentioning

confidence: 99%

“Let's Twist Again”Double-Stranded, Triple-Stranded, and Circular Helicates

2001

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“…Among the numerous applications of the lanthanide compounds, 30 the replacement of radio-analytical assays, the sensing of various organic molecules, the chemical labeling of DNA or the specific cleavage of RNA, the production of new phosphors and the design of MRI contrast agents can be mentioned. 33 The characterization of bimetallic triple-stranded helicates by crystallography, 27,28,[34][35][36][37] NMR, 37,38 mass spectrometry, [39][40][41] electrochemistry, 42 spectrophotometry, and potentiometry 12,13,15,25,43,44 has pointed out the main structural features involved in the formation of a helical architecture. The nature of the binding sites and of the cations imposes the number of strands.…”

Section: Introductionmentioning

confidence: 99%

Self-Assembly Mechanism of a Bimetallic Europium Triple-Stranded Helicate

et al. 2003

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We report the self-assembly process of a supramolecular edifice based on the coordination of europium(III) by a ditopic strand L bearing tridentate bis(benzimidazolyl)pyridine subunits. Varying the metal/ligand ratio and using a fruitful combination of electrospray mass spectrometry and absorption spectrophotometry, we characterized three major complexes (EuL(2), Eu(2)L(2), and Eu(2)L(3)) in acetonitrile. Kinetic investigations showed an alternative "braiding" and "keystone" mechanism leading to Eu(2)L(3). The formation mechanism of the dinuclear triple-stranded helicate, which is mainly governed by electrostatic interactions, goes via the "side-by-side" Eu(2)L(2) intermediate. Our thermodynamic and kinetic data allow the prediction of the apparent "magic" self-assembly of Eu(2)L(3) which is fast and efficient only under a strict set of conditions.

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“…The family of double-stranded helicates generated from ligands with multiple diimine binding domains and transition-metal ions of various binding geometries presents such properties. However, if their structures are well characterized by crystallography [6] [7] [28], NMR [6] [7] [29], mass spectrometry [30] [31], or electrochemistry [32], few physico-chemical properties are available in the literature [33] [34]. Spectrophotometric and thermodynamic parameters of triple helical lanthanide complexes have been reported [35].…”

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confidence: 99%

Self-Assembly of Tricuprous Double Helicates: Thermodynamics, Kinetics, and Mechanism

Fatin‐Rouge¹,

Blanc²,

Pfeil

et al. 2001

HCA

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Dedicated to Edgar Heilbronner on the occasion of his 80th birthdayWe report in this paper the coordination and kinetic properties of two oligobipyridine strands, which contain three 2,2'-bipyridine subunits separated by oxydimethylene bridges, the 4,4'-bis(CONET 2 )-substituted L and the 4,4'-bis(CO 2 Et)-substituted L'. Spectrophotometric measurements allowed the characterization of thermodynamic complexes and kinetic intermediates* which are involved in the self-assembly process of L 2 Cu 3 and L ' 2 Cu 3 helicates. The reaction presents positive cooperativity for the binding of two 2,2'-bipyridine strands to the cuprous cations. While reactive kinetic intermediates* present distorted coordination geometries around Cu I , the final rearrangement of the tricuprous bistranded helicates allows more closely tetrahedral coordination of each cation and reduces the interactions. Differences in the bulkiness and electronic properties of the L and L' substituents do not affect significantly the stability of the corresponding helicates, but greatly influence binding rates in the self-assembly process.Introduction. ± In recent years, creating molecules that are programmed by virtue of their structure and binding sites to spontaneously organize themselves into supramolecular architectures held together by metal coordination has aroused the interest of chemists [1 ± 5] (for recent reviews on metal-ion-mediated self-assembly, see, e.g., [2] ], were generated. To design such species presenting specific structural and functional features, it is of great importance to establish the rules by which control the assembly process can be achieved through chemical programming by means of suitable components and assembling algorithms [1] [5]. In the self-assembly of helicates, three main structural features determine the nature and shape of the helical species formed. The binding sites impose the number of strands able to coordinate metal ions with a given geometry. Bidentate or tridendate subunits combined, respectively, with metal ions of tetrahedral [6] [7] and of octahedral [6] [24] coordination geometry produce double helical polynuclear species, while triple helical complexes are formed with bidentate ligands and octahedrally coordinated metal ions [25]. Taking into account these properties, double-helical mixed-valence [14] heteronuclear [26] or heterostranded [27] complexes have been synthesized. However, not every combination of oligomultidentate ligands with metal ions will give helical structures, and the spacers between the metal binding sites play an important role. They should be flexible enough to allow the ligand to bind

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Electrochemical characterization of a self-assembled double strand copper complex composed of three Cu+ and two ligands containing bis(bipyridine) bithiophene

Cited by 11 publications

References 24 publications

“Let's Twist Again”Double-Stranded, Triple-Stranded, and Circular Helicates

“Let's Twist Again”Double-Stranded, Triple-Stranded, and Circular Helicates

Self-Assembly Mechanism of a Bimetallic Europium Triple-Stranded Helicate

Self-Assembly of Tricuprous Double Helicates: Thermodynamics, Kinetics, and Mechanism

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