Identification and Characterization of Redox Sites in Supramolecular Systems and Their Relevance for the Design of Photoactive Devices. Ru(II)/C60-Based Donor-Acceptor Dyads

2001 ◽  
Vol 66 (2) ◽  
pp. 276-290 ◽  
Author(s):  
Maurizio Carano ◽  
Paola Ceroni ◽  
Michele Maggini ◽  
Massimo Marcaccio ◽  
Enzo Menna ◽  
...  
Keyword(s):  
Ruthenium Complex ◽  
Azomethine Ylide ◽  
Electronic Interactions ◽  
Redox Sites ◽  
Ligand Charge Transfer ◽  
Donor Acceptor ◽  
Dinuclear Ruthenium ◽  
Photophysical Studies ◽  
Covalently Linked

Two dyads consisting of a mononuclear or a dinuclear ruthenium complex covalently linked to a fullerenopyrrolidine through a rigid androstane spacer, have been prepared through azomethine ylide cycloaddition to C60. Electrochemical and photophysical studies revealed that ground-state electronic interactions between the dinuclear ruthenium chromophore and the fullerenopyrrolidine moiety are small. The redox series observed for the dyads correspond to the superimposition of the reduction patterns of the fullerene core and of the Ru(II)-bipyridine moieties. The results of the electrochemical investigation allow us to rationalize the photophysical behaviour of the two species by identifying the thermodynamically allowed and forbidden routes for the deactivation of the Ru-based metal-to-ligand charge transfer (MLCT) excited state.

Phthalocyanine-corannulene conjugates: Synthesis, complexation studies with a pyridyl-functionalized C60 fullerene, and photophysical properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 410-415 ◽  
Author(s):  
Juan A. Suanzes ◽  
Sumit Chaurasia ◽  
Rafael M. Krick Calderon ◽  
Dirk M. Guldi ◽  
Giovanni Bottari ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Supramolecular Interactions ◽  
C60 Fullerene ◽  
Time Resolved ◽  
Complexation Studies ◽  
Donor Acceptor ◽  
Photophysical Studies ◽  
Covalently Linked ◽  
Photoinduced Charge

We report here the synthesis and characterization of some novel Zn(II)phthalocyanine (Pc)-corannulene conjugates and their complexation ability towards a pyridyl-functionalized C[Formula: see text] fullerene through metal-ligand supramolecular interactions. Steady-state and time-resolved photophysical studies carried out on these electron donor–acceptor (D–A) Zn(II)Pc-corannulene/C[Formula: see text] ensembles indicate the formation of photogenerated charge-separated species. Interestingly, a stabilization of the photoinduced charge-separated state is observed in the case of the D–A supramolecular complexes comprising the corannulene-substituted Zn(II)Pcs when compared to their non-corannulene functionalized Zn(II)Pc analogues. We rationalize this stabilizing effect of the charge-separated state exerted by the corannulene as a result of the increased [Formula: see text]-extension and augmented hydrophobicity of the Zn(II)Pc core by the covalently-linked polyaromatic hydrocarbon (PAH) fragment.

A computational study of a cyano-bridged dinuclear ruthenium complex containing the non-innocent methylpyrazinium ligand

2004 ◽  
Vol 82 (6) ◽  
pp. 1102-1111 ◽  
Author(s):  
A BP Lever
Keyword(s):  
Density Functional ◽  
Ruthenium Complex ◽  
Computational Study ◽  
Electronic Coupling ◽  
Functional Theory ◽  
Electronic Interactions ◽  
Ligand Charge Transfer ◽  
Charge Transfer Transitions ◽  
Dinuclear Ruthenium ◽  
S Model

The properties of a series of complexes trans-[LRu(NH3)4-NC-Ru(NH3)4(methylpyrazinium)]n+ where L is an anion (Cl–, F–, CN–, OH–) or neutral ligand (CO, H2O, pyridine, CH3NO2) were analyzed using density functional theory. The objective was to probe the change in electronic coupling between the two ruthenium atoms and between ruthenium and the non-innocent methylpyrazinium ligand as L is varied. Molecular orbital coefficients and optical spectra were derived. The electronic interactions involved are seen to be quite sensitive to the charge on the ruthenium to which the ligand L is attached as L is varied. Exchange (K) and Coulomb (J) energies are also calculated, using the INDO/S model, for the various metal-to-ligand charge-transfer transitions. K correlates well with the energy and intensity of the transitions and specifically with the variation in delocalization induced by variation of L.Key words: DFT, ruthenium, non-innocent ligand, methylpyrazinium, ZINDO.

Electrochemical and spectroelectrochemical characterization of covalently-linked donor–acceptor model compound

1998 ◽  
Vol 43 (18) ◽  
pp. 2693-2698 ◽  
Author(s):  
Jie Zhang ◽  
Hao-ran Sun ◽  
Guo-yu Yang ◽  
Ke Wen ◽  
Lian-xiang Yu ◽  
...  
Keyword(s):  
Model Compound ◽  
Donor Acceptor ◽  
Covalently Linked

Perhalogenated porphyrins as a sink of excitation energy in porphyrin heterodimers

2002 ◽  
Vol 06 (10) ◽  
pp. 643-652 ◽  
Author(s):  
Mariano Venanzi ◽  
Pietro Tagliatesta ◽  
Alessandra Pastorini ◽  
Patrizia Mari ◽  
Fausto Elisei ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Flash Photolysis ◽  
Triplet States ◽  
Acceptor Pair ◽  
Electronic Interactions ◽  
Heavy Atoms ◽  
New Family ◽  
Donor Acceptor ◽  
Covalently Linked ◽  
Derivatives Of

The photophysics of a new family of free-base and zinc derivatives of meso- tetraphenylporphyrin heterodimers have been studied by UV-vis absorption, fluorescence and nanosecond flash photolysis techniques. An almost complete (≈99%) and directionally controlled transfer of excitation energy from a donor porphyrin moiety was obtained by multiple bromination (four and eight Br substituents in the two series of compounds investigated) on the β-pyrrole positions of the acceptor porphyrin molecule. The covalently linked porphyrin dimers populate almost exclusively low energy triplet states because of the extremely efficient intramolecular singlet-to-triplet inter system crossing (ISC) process which is enhanced by the multiple heavy atoms substitutions. The nature of the electronic interactions determining the actual relaxation pathway followed by the porphyrin donor-acceptor pair is discussed.

Preparation and characterization of a new dinuclear ruthenium complex with BDPX ligand and its catalytic hydrogenation reactions for cinnamaldehyde

2010 ◽  
Vol 22 (7) ◽  
pp. 738-742 ◽  
Author(s):  
Yuan-You Tang ◽  
Rui-Xiang Li ◽  
Xian-Jun Li ◽  
Ning-Bew Wong ◽  
Kim-Chung Tin ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Ruthenium Complex ◽  
Hydrogenation Reactions ◽  
Dinuclear Ruthenium

Single-wall carbon nanotube porphyrin nanoconjugates

2007 ◽  
Vol 11 (06) ◽  
pp. 442-447 ◽  
Author(s):  
Christian Ehli ◽  
Stéphane Campidelli ◽  
Fulvio G. Brunetti ◽  
Maurizio Prato ◽  
Dirk M. Guldi
Keyword(s):  
Excited State ◽  
Carbon Nanotube ◽  
Transient Absorption ◽  
Spectroscopic Characterization ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon ◽  
Low Degree ◽  
Donor Acceptor ◽  
Covalently Linked

We describe the synthesis, microscopic and spectroscopic characterization of a novel donor-acceptor prototype, namely, a single wall carbon nanotube (SWNT) nanoconjugate bearing a covalently linked free base porphyrin ( H 2 P ). In the characterized SWNT- H 2 P nanoconjugate the electronic features of SWNT are largely retained, when compared to pristine SWNT. In fact, carefully controlled reaction conditions lead to a low degree of SWNT functionalization, as evidenced by the preservation of the SWNT van Hove singularities. As a consequence, the overall SWNT loading with H 2 P is so low that in the ground state, the H 2 P features are barely seen, which is different from the excited state, where features of H 2 P are clearly discernable. For example, fluorescence and transient absorption characteristics corroborate, unequivocally, the formation of the H 2 P singlet excited state, which is, however, impacted by the presence of SWNT.

Synthesis and characterization of the monomer ruthenium complex of hypocrellin B

2005 ◽  
Vol 15 (12) ◽  
pp. 3067-3070 ◽  
Author(s):  
Jiahong Zhou ◽  
Jihua Liu ◽  
Yuying Feng ◽  
Shaohua Wei ◽  
Xiaotian Gu ◽  
...  
Keyword(s):  
Ruthenium Complex ◽  
Synthesis And Characterization ◽  
Hypocrellin B
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