A Photophysical and Electrochemical Investigation on a Phenylacetylene Macrocycle Containing Two 2,2′‐Bipyridine Units, Its Protonated Forms, and Ru<sup>II</sup> and Os<sup>II</sup> Complexes

Venturi, Margherita; Marchioni, Filippo; Balzani, Vincenzo; Opris, Dorina M.; Henze, Oliver; Schlüter, A. Dieter

doi:10.1002/ejoc.200300384

Cited by 25 publications

(12 citation statements)

References 21 publications

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“…a nickel porphyrin homologues [34][35][36], [Ni(OBTTAP)] and (bpy) 2 Ru II /(phen) 2 Ru II [37,38]. Hence, the emission characteristics of these supramolecular systems are expected to be an amalgamation of the two.…”

Section: Emission Spectramentioning

confidence: 99%

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Prasad

Kumar

2005

J. Porphyrins Phthalocyanines

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The (bpy) 2 Ru II and (phen) 2 Ru II moieties were linked to [Ni(OBTTAP)] 1, periphery through coordinate bonds in order to synthesize cationic di-and pentanuclear complexes 2-5 that were obtained as PF 6 -salts. They were characterized by IR, 1 H NMR, UV-vis, and mass spectral data. The electronic absorption, emission and redox data of these bichromophoric systems indicate the presence of a high degree of intercomponent electronic interaction. The position and relative intensities of the Soret and Q bands in these complexes is altered due to peripheral binding of the metal units. The compounds were non-emissive for the Q band excitation but, Soret excitation led to a strong S 2 emission, observed between 400-450 nm. In cyclic voltammetry, the compounds exhibited one Ru centered oxidation together with one or two OBTTAP centered oxidations. The Ru II /Ru III oxidations were observed at significantly lower potentials as compared to the corresponding simple maleonitrilebenzylthioether complexes and has been interpretted in terms of weaker dπ(S)−dπ(Ru) interactions.

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Section: Emission Spectramentioning

confidence: 99%

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Prasad

Kumar

2005

J. Porphyrins Phthalocyanines

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“…We have recently synthesized shape‐persistent macrocycles incorporating 2,2′‐bipyridine (bpy) ligands 11. Compound 1 (Scheme ) is particularly interesting since it can bridge two metal‐based units.…”

Section: Introductionmentioning

confidence: 99%

“…Compound 1 (Scheme ) is particularly interesting since it can bridge two metal‐based units. Its homodinuclear complexes [(bpy) 2 Ru( 1 )Ru(bpy) 2 ] 4+ and [(bpy) 2 Os( 1 )Os(bpy) 2 ] 4+ (hereafter called Ru II 1 Ru II and Os II 1 Os II , Scheme ) exhibit luminescence and reversible redox properties,11 as expected for weakly coupled metal centers.…”

Section: Introductionmentioning

confidence: 99%

Photoinduced Energy‐ and Electron‐Transfer Processes in Dinuclear Ru^II–Os^II, Ru^II–Os^III, and Ru^III–Os^II Trisbipyridine Complexes Containing a Shape‐Persistent Macrocyclic Spacer

et al. 2006

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The PF6- salt of the dinuclear [(bpy)2Ru(1)Os(bpy)2]4+ complex, where 1 is a phenylacetylene macrocycle which incorporates two 2,2'-bipyridine (bpy) chelating units in opposite sites of its shape-persistent structure, was prepared. In acetonitrile solution, the Ru- and Os-based units display their characteristic absorption spectra and electrochemical properties as in the parent homodinuclear compounds. The luminescence spectrum, however, shows that the emission band of the Ru(II) unit is almost completely quenched with concomitant sensitization of the emission of the Os(II) unit. Electronic energy transfer from the Ru(II) to the Os(II) unit takes place by two distinct processes (k(en) = 2.0x10(8) and 2.2x10(7) s(-1) at 298 K). Oxidation of the Os(II) unit of [(bpy)2Ru(1)Os(bpy)2]4+ by Ce(IV) or nitric acid leads quantitatively to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ complex which exhibits a bpy-to-Os(III) charge-transfer band at 720 nm (epsilon(max) = 250 M(-1) cm(-1)). Light excitation of the Ru(II) unit of [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ is followed by electron transfer from the Ru(II) to the Os(III) unit (k(el,f) = 1.6x10(8) and 2.7x10(7) s(-1)), resulting in the transient formation of the [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ complex. The latter species relaxes to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ one by back electron transfer (k(el,b) = 9.1x10(7) and 1.2x10(7) s(-1)). The biexponential decays of the [(bpy)2*Ru(II)(1)Os(II)(bpy)2]4+, [(bpy)2*Ru(II)(1)Os(III)(bpy)2]5+, and [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ species are related to the presence of two conformers, as expected because of the steric hindrance between hydrogen atoms of the pyridine and phenyl rings. Comparison of the results obtained with those previously reported for other Ru-Os polypyridine complexes shows that the macrocyclic ligand 1 is a relatively poor conducting bridge.

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“…In that respect, they allow to produce a variety of materials for many applications, such as metal ion chemosensing [7], electroluminescence [55], liquid crystals [56], or photoconductivity [57]. Conjugated polypyridine ligands are also being exploited as building-blocks for the constructions of nanostructures such as macrocycles [58] [59], hyperbranched structures [60], polytopic modules for nanoengineering [61], or self-assembled chromogenic ion sensors [62]. Moreover, this account emphasizes the behavior in the singlet excited-state but conjugated polypyridine ligands also allow to investigate triplet state properties.…”

Section: Resultsmentioning

confidence: 99%

Polypyridine ligands with extended π-conjugation: highly tunable fluorophores

Leroy‐Lhez¹,

Fagès²

2005

Comptes Rendus. Chimie

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A Photophysical and Electrochemical Investigation on a Phenylacetylene Macrocycle Containing Two 2,2′‐Bipyridine Units, Its Protonated Forms, and Ru^II and Os^II Complexes

Abstract: The phenylacetylene macrocycle 1, which incorporates two 2,2Ј-bipyridine (bpy) chelating units in opposite sites in its shape-persistent structure, shows an intense absorption band in the UV spectral region (λ max = 305 nm, ε max = 118000

Cited by 25 publications

References 21 publications

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Photoinduced Energy‐ and Electron‐Transfer Processes in Dinuclear Ru^II–Os^II, Ru^II–Os^III, and Ru^III–Os^II Trisbipyridine Complexes Containing a Shape‐Persistent Macrocyclic Spacer

Polypyridine ligands with extended π-conjugation: highly tunable fluorophores

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A Photophysical and Electrochemical Investigation on a Phenylacetylene Macrocycle Containing Two 2,2′‐Bipyridine Units, Its Protonated Forms, and RuII and OsII Complexes

Abstract: The phenylacetylene macrocycle 1, which incorporates two 2,2Ј-bipyridine (bpy) chelating units in opposite sites in its shape-persistent structure, shows an intense absorption band in the UV spectral region (λ max = 305 nm, ε max = 118000

Cited by 25 publications

References 21 publications

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

Photoinduced Energy‐ and Electron‐Transfer Processes in Dinuclear RuII–OsII, RuII–OsIII, and RuIII–OsII Trisbipyridine Complexes Containing a Shape‐Persistent Macrocyclic Spacer

Polypyridine ligands with extended π-conjugation: highly tunable fluorophores

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A Photophysical and Electrochemical Investigation on a Phenylacetylene Macrocycle Containing Two 2,2′‐Bipyridine Units, Its Protonated Forms, and Ru^II and Os^II Complexes

Photoinduced Energy‐ and Electron‐Transfer Processes in Dinuclear Ru^II–Os^II, Ru^II–Os^III, and Ru^III–Os^II Trisbipyridine Complexes Containing a Shape‐Persistent Macrocyclic Spacer