- Photodriven Multi-electron Storage in Disubstituted RuII Dppz Analogues
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Four derivatives of the laminate acceptor ligand dipyrido-[3,2-a:2′,3′-c]phenazine (dppz) and their corresponding ruthenium complexes, [Ru(phen)2(dppzX2)]2+, were prepared and characterized by NMR spectroscopy, ESI-MS, and elemental analysis. The new ligands, generically denoted dppzX2, were symmetrically disubstituted on the distal benzene ring to give 10,13-dibromodppz (dppz-p-Br), 11,12-dibromodppz (dppz-o-Br), 10,13-dicyanodppz (dppz-p-CN), 11,12-dicyanodppz (dppz-o-CN). Solvated ground state MO calculations of the ruthenium complexes reveal that these electron-withdrawing substituents not only lower the LUMO of the dppz ligand (dppz(CN)22dppz), but that the para disubstitution results in a lower LUMO than the ortho disubstitution (dppz-p-CN(dppz-o-CN), and dppz-p-Brdppz-o-Br). The validity of the calculations was confirmed experimentally using cyclic voltammetry. Of the complexes evaluated in this study, only the dicyanodppz complexes showed multiple dppz-based reductions prior to reduction of the phen ligands. The capacity to form singly and doubly reduced dppz-based anions at modest reduction potentials was confirmed using a combination of spectroelectrochemical and chemical titration methods. When subjected to photolysis with visible light in the presence of a sacrificial donor, such as triethylamine, both cyano complexes showed multi-electron reduction. The other complexes only show a single reduction.
- Aslan, Joseph M.,Boston, David J.,MacDonnell, Frederick M.
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- A reliable route to 1,2-diamino-4,5-phthalodinitrile
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Starting from o-phenylenediamine, we have developed a new and reliable route to 1,2-diamino-4,5-phthalodinitrile that is based on the reductive desulfurisation of 5,6-dicyano-2,1,3-benzothiadiazole with sodium borohydride. The reaction sequence uses only
- Burmester, Christian,Faust, Ruediger
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- Solution-processable n-type semiconductors based on unsymmetrical naphthalene imides: Synthesis, characterization, and applications in field-effect transistors
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A series of unsymmetrical naphthalene imide derivatives (1-5) with high electron affinity was synthesized and used in n-channel organic field-effect transistors (OFETs). They have very good solubility in common organic solvents and good thermal stability up to 320 °C. Their photophysical, electrochemical, and thermal properties were investigated in detail. They showed low-lying LUMO energy levels from -3.90 to -4.15 eV owing to a strong electron-withdrawing character. Solution-processed thin-film OFETs based on 1-4 were measured in both N2 and air. They all showed n-type FET behavior. The liquid-crystalline compounds 1 a, 1 b, and 3 showed good performance owing to the self-healing properties of the film in the liquid-crystal phase. Compound 3 has an electron mobility of up to 0.016 cm 2 V-1 s-1 and current on/off ratios of 10 4-105.Copyright
- Shao, Jinjun,Chang, Jingjing,Chi, Chunyan
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- A novel fully conjugated phenanthroline-appended phthalocyanine: Synthesis and characterisation
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The synthetic route to a new fully conjugated phenanthroline appended phthalocyanine is described. This compound has been fully characterised by elemental analysis, UV-VIS, IR, MS and 1H NMR spectroscopy.
- Rusanova, Julia,Pilkington, Melanie,Decurtins, Silvio
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- Substituted benzazoloporphyrazines for polymerization and surface attachment and articles formed therefrom
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The present invention provides an article of manufacture formed from a substrate and a benzazoloporphyrazine bound to the substrate. The article may take a variety of different forms and may be for example an electrochromic display, a molecular capacitor, a battery, a solar cell, or a molecular memory device. Methods of making such articles, along with compounds, methods and intermediates useful for making such benzazoloporphyrazines, are also described.
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Page/Page column 26
(2011/02/18)
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- Synthesis, properties and in vitro photodynamic activity of water-soluble azaphthalocyanines and azanaphthalocyanines
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In this work zinc azaphthalocyanines (AzaPcs) from the group of tetrapyrazinoporphyrazines and zinc azanaphthalocyanines from the group of tetra[6,7]quinoxalinoporphyrazines (TQP) with eight diethylaminoethylsulfanyl substituents were synthesized. Tertiary amines were later quaternized with ethyl iodide to obtain water-soluble photosensitizers (PSs). Quaternized compounds showed high singlet oxygen quantum yields as determined in DMF by monitoring decomposition of 1,3-diphenylisobenzofuran. In water medium, quaternized AzaPc derivatives appeared in monomeric form in a wide range of concentrations while quaternized TQP derivatives showed aggregation at higher concentrations (over 1 μm). Photodynamic activity was tested on Hep2 cells using light of λ > 640 nm. Both quaternized dyes showed high photodynamic activity (IC 50 = 104 and 220 nm for AzaPc and TQP, respectively). Dark toxicity was not detected even at the highest concentration used in in vitro tests (200 μm) which indicates a promising therapeutic index of these new substances. Tested compounds localized inside the cells mainly within the lysosomes thus suggesting an endocytic mechanism of cellular uptake. No localization within mitochondria was detected. A great advantage of TQP derivatives over other PSs is their very strong absorption at 747 nm that allows activation at wavelengths penetrating deeper into human tissues.
- Zimcik, Petr,Miletin, Miroslav,Radilova, Hana,Novakova, Veronika,Kopecky, Kamil,Svec, Jaroslav,Rudolf, Emil
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scheme or table
p. 168 - 175
(2010/04/04)
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- Synthesis and potent antifungal activity against Candida species of some novel 1H-benzimidazoles
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(Chemical Equation Presented) A series of 47 novel N1-alkylated- 2-aryl-5(6)-substituted-1H-benzimidazoles and their three novel indole analogues were synthesized and evaluated for in vitro antifungal activities against Candida species by the tube dilution method. The results showed that compounds 79 and 80, having pyridine at the position C-2, of benzimidazoles exhibited the greatest activity with MIC values of 6.25-3.12 μg/mL. Indole analogues 108-110 have no inhibitory activity.
- Goeker, Hakan,Alp, Mehmet,Ates-Alagoez, Zeynep,Yildiz, Sulhiye
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scheme or table
p. 936 - 948
(2009/12/05)
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- Synthesis of a new trans-A2B2 phthalocyanine motif as a building block for rodlike phthalocyanine polymers
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Polyphthalocyanines have potential application in the development of electronic materials. One-dimensional polyphthalocyanines are accessible through monomers having a trans-A2B2 structure, but the preparation of a truly linear polyphthalocyanine is challenging because of limitations imposed by the geometry of phthalocyanines and the methodology for their synthesis. Benzimidazoporphyrazines are a known class of extra-annulated phthalocyanines. A trans-A2B2 benzimidazoporphyrazine is geometrically suitable for the preparation of rodlike polymers. A new synthesis of benzimidazoporphyrazines is presented as a stepping stone to the synthesis of trans-A2B2 benzimidazoporphyrazines.
- Youngblood, W. Justin
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p. 3345 - 3356
(2007/10/03)
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- Acetylenic quinoxalinoporphyrazines as photosensitisers for photodynamic therapy
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A range of lipo- and hydrophilic derivatives of the new class of octaalkynyl tetra-[6,7]-quinoxalinoporphyrazines (TQuiPors), analogues of the naphthalocyanines, were prepared in two steps starting from functionalised hexa-1,5-diyne-3,4-diones. Divalent zinc and magnesium ions were introduced into the macrocyclic core. Whereas the triisopropylsilyl-, 3,5-di-tert-butylphenyl- and 4-triisopropylsilyloxyphenyl-terminated acetylenic TQuiPors are lipophilic and hence soluble in standard organic solvents, a polyethylene glycol-substituted derivative was found to dissolve in DMSO as well as in ethanol/water mixtures. The new chromophores are characterised by intense UV/Vis/NIR absorptions, most notably by bands at 770 nm with extinction coefficients exceeding 500000M-1 cm-1. With a view to possible photodynamic therapy applications, the potency of the chromophores to sensitise the formation of singlet oxygen was examined, both qualitatively using a 1,3-diphenylisobenzofuran assay, and quantitatively by the determination of the singlet oxygen quantum yields. It was found that all TQuiPors produce singlet oxygen when irradiated in the presence of air. In particular, the octaalkynyl Zn-TQuiPor generates singlet oxygen with a quantum yield of 56%, thereby rivalling, and, in conjunction with its absorption profile, even exceeding the standards set by established PDT agents. The photostabilities of the TQuiPors were assessed and generally found to be satisfactory, but dependent on the solvent and the wavelength of the incident light.
- Mitzel, Frieder,FitzGerald, Simon,Beeby, Andrew,Faust, Ruediger
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p. 1233 - 1241
(2007/10/03)
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- Octaalkynyltetra[6,7]quinoxalinoporphyrazines: A new class of photosensitisers with potential for photodynamic therapy
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Acetylene-substituted tetra[6,7]quinoxalinoporphyrazines, obtained in two steps from dialkynyl-1,2-diones and 1,2-diamino-4,5-dicyanobenzene, show intense absorptions in the near infrared and have photooxidising properties that make them promising candida
- Mitzel,FitzGerald,Beeby,Faust
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p. 2596 - 2597
(2007/10/03)
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- Synthesis and properties of 5,6-dicyanobenzimidazole and porphyrazines derived from it
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4,5-Diaminophthalodinitrile was reacted with formic acid to synthesize 5,6-dicyanobenzimidazole which was used as starting material for preparing a metal-free phthalocyanine with four annelated imidazole moieties, as well as its copper complex. The effect
- Kudrik,Shaposhnikov,Balakirev
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p. 1321 - 1324
(2007/10/03)
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