| 1. |
- He, J. J., et al.
(author)
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Phthalocyanine-sensitized nanostructured TiO2 electrodes prepared by a novel anchoring method
- 2001
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 17:9, s. 2743-2747
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Journal article (peer-reviewed)abstract
- A novel method for anchoring phthalocyanines substituted with ester groups onto nanostructured TiO2 films is described. Such phthalocyanines did not adsorb on nanostructured TiO2 film by the ordinary methods. In our new method, the TiO2 film is pretreated with (CH3)(3)COLi to change the surface hydroxyl groups (-OH) into oxygen anions (-O-), thus making the surface more reactive toward the ester functionalities of the dye. The dye can then be anchored onto the semiconductor surface through the produced carboxylate group(s). The amount of anchored dye on the semiconductor shows a dependence on both the time of base treatment and the time of dye treatment. Electrodes treated with the free base phthalocyanine and zinc phthalocyanine were characterized by absorption spectroscopy, photocurrent action spectroscopy, and photocurrent-photovoltage measurements. The homogeneous blue-green color and the absorption bands in the far-red region are indicative of an attachment of the dye on TiO2 film. A monochromatic incident photo-to-current conversion efficiency of 4.3 % was achieved at 690 nm for a cell where the base-treated electrode was treated with ZnPcBu.
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| 2. |
- He, Jianjun, et al.
(author)
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Modified phthalocyanines for efficient near-IR sensitization of nanostructured TiO2 electrode
- 2002
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 124:17, s. 4922-4932
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Journal article (peer-reviewed)abstract
- A zinc phthalocyanine with tyrosine substituents (ZnPcTyr), modified for efficient far-red/near-IR performance in dye-sensitized nanostructured TiO2 solar cells, and its reference, glycine-substituted zinc phthalocyanine, (ZnPcGly), were synthesized and characterized. The compounds were studied spectroscopically, electrochemically, and photoelectrochemically. Incorporating tyrosine groups into phthalocyanine makes the dye ethanol-soluble and reduces surface aggregation as a result of steric effects. The performance of a solar cell based on ZnPcTyr is much better than that based on ZnPcGly. Addition of 3alpha,7alpha-dihydroxy-5beta-cholic acid (cheno) and 4-tert-butylpyridine (TBP) to the dye solution when preparing a dye-sensitized TiO2 electrode diminishes significantly the surface aggregation and, therefore, improves the performance of solar cells based on these phthalocyanines. The highest monochromatic incident photo-to-current conversion efficiency (IPCE) of similar to24% at 690 nm and an overall conversion efficiency (eta) of 0.54% were achieved for a cell based on a ZnPcTyr-sensitized TiO2 electrode. Addition of TBP in the electrolyte decreases the IPCE and eta considerably, although it increases the open-circuit photovoltage. Time-resolved transient absorption measurements of interfacial electron-transfer kinetics in a ZnPoTyr-sensitized nanostructured 702 thin film show that electron injection from the excited state of the dye into the conduction band of TiO2 is completed in similar to500 fs and that more than half of the injected electrons recombines with the oxidized dye molecules in similar to300 ps. In addition to surface aggregation, the very fast electron recombination is most likely responsible for the low performance of the solar cell based on ZnPcTyr.
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| 3. |
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| 4. |
- Kóródi, F., et al.
(author)
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Fused 1,2,4-TriazoIe Heterocycles. IV. Synthesis of Four New Heterocyclic Ring Systems of [1,2,4]Triazolo[1,3]thiazinoquinolines
- 1997
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In: Journal of Heterocyclic Chemistry. - : Wiley. - 0022-152X .- 1943-5193. ; 34:4, s. 1275-1281
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Journal article (peer-reviewed)abstract
- Syntheses of 5H-[1,2,4]triazolo[5′1′:2,3][1,3]thiazino[5,4-c]quinolines 8, 5H-[1,2,4]triazolo[3′,4′:2,3][1,3]thiazino[5,4-c]quinolines 9, 5H-[1,2,4]triazolo[5′1′:2,3][1,3]thiazino[5,6-c]quinolines 14 and 5H-[1,2,4]triazolo[3′,4′:2,3][1,3]thiazino[5,6-c]quinolines 15 are described starting from 4-chloro-3-chloromethylquinaldine (4) and 1,2,4-triazole-5-thiols 5 taking advantage of different reactivity of the chlorine atoms of 4 under different reaction conditions. The structures of products 8, 9, 14 and 15 and the intermediates leading to them were confirmed by desulfurization, unequivocal syntheses and nmr spectroscopy as well.
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| 5. |
- Kóródi, F., et al.
(author)
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Fused 1,2,4-triazole heterocycles. I. Synthesis of novel [1,2,4]triazolo[5′,1′:2,3][1,3]thiazino[6,5-b]quinolines
- 1992
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In: Heterocycles. - : The Japan Institute of Heterocyclic Chemistry. - 0385-5414 .- 1881-0942. ; 34:9, s. 1711-1720
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Journal article (peer-reviewed)abstract
- Derivatives of a new heterocyclic ring system of [1,2,4]triazolo[5′,1′: 2,3][1,3]thiazino[6,5-b]quinolines (4,5,6,7 and 8) have been synthesised by the reaction of 2-chloroquinoline-3-carbaldehyde derivatives (1 and 2) with 1,2,4-triazole-5-thiols (3), and subsequent transformations of the hydroxy group of 11-hydroxy[1,2,4]triazolo[5′,1′: 2,3][1,3]thiazino[6,5-b]quinoline (4a).
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| 6. |
- Kóródi, F., et al.
(author)
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Fused 1,2,4-triazole heterocycles. iii. syntheses and structures of novel [1,2,4]triazolo[1,3]thiazinoquinolines
- 1995
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In: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 1:4, s. 297-306
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Journal article (peer-reviewed)abstract
- Synthetic methods are described for the preparation of 5H-[1,2,4]triazolo[5‘,1’:2,3][1,3]thiazino[4,5-b]quinolines 5, 5H-[1,2,4]triazolo[3',4’:2,3][1,3]thiazino[4,5-b]quinolines 6, 11 H-[1,2,4]triazolo[5‘, 1 ':2,3][1,3]thiazino[6,5-b]quinoline 13 and 11H-[1,2,4]triazolot[3',4’:2,3][1,3]thiazino[6,5-b]quinoline 14 starting from 2-chloro-3-chloromethylquinoline 1 and 1,2,4-triazole-5-thiols 2. Different reactivity of the chlorine atoms of 1 under different reaction conditions, and a new rearrangement were observed during elaboration of these methods. The structures of the products 5, 6,13,14 and the intermediates leading to them were confirmed by desulfurisation reactions, unequivocal syntheses and nmr spectroscopy.
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| 7. |
- Szabo, Zoltan, Associate professor, et al.
(author)
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1H and 13C NMR study of novel fused 1,2,4‐triazole heterocycles
- 1992
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In: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:11, s. 1111-1116
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Journal article (peer-reviewed)abstract
- The 1H and 13C NMR spectra of some novel 1,2,4‐triazolo [1,3] thiazinoquinoline isomeric pairs are interpreted in terms of structural assignments. The structure of most compounds has been confirmed by NOE difference spectroscopy. Characteristic differences have been observed in both 1H and 13C NMR spectra of these isomeric Pairs: some of the 1H and 13C chemical shifts, and also the one bond 13C1H couplings of triazole protons, differ consistently in the NMR spectra of the isomers. The coupling constants have been determined using a combination of INEPT and chemical shift selective filtering.
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| 8. |
- Yanagisawa, M., et al.
(author)
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Ruthenium phthalocyanines with axial carboxylate ligands. Synthesis and function in solar cells based on nanocrystalline TiO2
- 2002
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In: Journal of Porphyrins and Phthalocyanines. - 1088-4246 .- 1099-1409. ; 6:3, s. 217-224
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Journal article (peer-reviewed)abstract
- The synthesis and characterization of phthalocyaninato-ruthenium (PcRu) complexes with potential functional axial ligands are described. The solubility of these PcRu complexes was much improved compared to their parent phthalocyanines without Ru, enabling purification by normal flash column chromatography and also NMR measurements in common solvents (e. g. DMSO-d(6) and CDCl3). Adsorption of these phthalocyanine dyes onto the surface of a semiconductor through the carboxyl group(s) in the axial ligands prevents to some extent formation of H-aggregates, which is typical for phthalocyanines. It also prevents stacking of the dye molecules on the surface. The photovoltaic behavior of sandwich solar cells based on nanostructured TiO2 films sensitized by these PcRu complexes was studied under irradiation with visible light. For a solar cell based on bis(4-carboxypyridine)-phthalocyaninato ruthenium(II) (1) sensitized nanoporous-nanocrystalline TiO2, a monochromatic incident photon-to-current conversion efficiency (IPCE) of 21% was obtained at 640 nm. The overall conversion efficiency (eta) was 0.61%, which is one of the best results for a solar cell based on a phthalocyanine dye. For a cell based on (4-carboxypyridine)-(4-(2-ethoxy)ethyloxycarbonylpyridine)-2,3,9,10,16,17,23,24-octa(n-pentyloxy)-phthalocyaninato ruthenium(II) (5) sensitized TiO2, a IPCE of 6.6% at 640 nm and eta of 0.58% were obtained.
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| 9. |
- Yanagisawa, M., et al.
(author)
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Synthesis of phthalocyanines with two carboxylic acid groups and their utilization in solar cells based on nanostructured TiO2
- 2004
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In: Journal of Porphyrins and Phthalocyanines. - 1088-4246 .- 1099-1409. ; 8:10, s. 1228-1235
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Journal article (peer-reviewed)abstract
- A way of anchoring unsymmetrical phthalocyaninato-metal complexes (metal ion: zinc and ruthenium) is described. The synthesis and characterization of these complexes are presented. In case of the zinc complex, the obtained product is an aggregate, while only the monomer is obtained in the case of the ruthenium derivative. Both complexes could be attached onto the TiO2 surface by using the reported method. Both dyes are expected to form monolayers with dye molecules standing on the surface of nano-structured TiO2, forming higher-order aggregates with the zinc but not with the ruthenium complex. A highest monochromatic incident photo-to-current conversion efficiency (IPCE) of 1.6% at 690 nm was obtained for a solar cell based on the Pc-Zn sensitized nano-structured TiO2 electrode, while an IPCE of 23% at 630 nm was obtained for the Pc-Ru sensitized electrode. Overall conversion efficiencies (eta) at a simulated AM 1.5 (100 W.m(-2)) of 0.03% and 0.40% for the zinc and ruthenium complexes were achieved, respectively. The difference in efficiencies could be due to the formation of face-to-face aggregation in the former case. This work shows that the ruthenium complex, with two axial methylpyridine ligands, does not form aggregates in solution nor on the surface of TiO2, making it possible for further construction of supramolecular systems with such types of phthalocyanine.
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