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31.
Synthesis and Transformations of 5‐Chloro‐2,2′‐Dipyrrins and Their Boron Complexes, 8‐Chloro‐BODIPYs 下载免费PDF全文
Haijun Wang Prof. M. Graça H. Vicente Dr. Frank R. Fronczek Prof. Kevin M. Smith 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):5064-5074
Symmetric dipyrrylketones 1 a , b were synthesized in two steps from the corresponding α‐free pyrroles, by reaction with thiophosgene followed by oxidative hydrolysis under basic conditions. The dipyrrylketones produced the corresponding 5‐chloro‐dipyrrinium salts or 5‐ethoxy‐dipyrrins on reaction with phosgene or Meerwein’s salt, respectively. Boron complexation of the dipyrrins afforded the corresponding 8‐functionalized BODIPYs (borondipyrromethenes) in high yields. The 5‐chloro‐dipyrrinium salts reacted with methoxide or ethoxide ions to produce monopyrrole esters, presumably via a 5,5‐dialkoxy‐dipyrromethane intermediate. In contrast, 8‐chloro‐BODIPYs underwent a variety of nucleophilic substitutions of the chloro group in the presence of alkoxide ions, Grignard reagents, and thiols. In the presence of excess alkoxide or Grignard reagent, at room temperature or above, substitution at the boron center also occurred. The 8‐chloro‐BODIPY was a particularly useful reagent for the preparation of 8‐aryl‐, 8‐alkyl‐, and 8‐vinyl‐substituted BODIPYs in very high yields, using Pd0‐catalyzed Stille cross‐coupling reactions. The X‐ray structures of eleven BODIPYs and two pyrroles are presented, and the spectroscopic properties of the synthesized BODIPYs are discussed. 相似文献
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From superhydrophobic‐ to superhydrophilic‐patterned poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) architectures as a novel platform for biotechnological applications 下载免费PDF全文
Vanessa F. Cardoso Ana R. Machado Vânia C. Pinto Paulo J. Sousa Gabriela Botelho Graça Minas Senentxu Lanceros‐Méndez 《Journal of Polymer Science.Polymer Physics》2016,54(18):1802-1810
The manufacture of three‐dimensional patterned electroactive poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) microstructures with tailored architecture, morphology, and wettability is presented. The patterned microstructures are fabricated using a simple, effective, low cost, and reproducible technique based on microfluidic technology. These novel structures can represent innovative platforms for advanced strategies in a wide range of biotechnological applications, including tissue engineering, drug delivery, microfluidic, and sensors and actuators devices. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1802–1810 相似文献
34.
Maderna A Huertas R Hawthorne MF Luguya R Vicente MG 《Chemical communications (Cambridge, England)》2002,(16):1784-1785
A boron-rich, water-soluble porphyrin conjugate was synthesized by coupling of two carboranyl alcohols with 2-chlorophenoxyphosphorus dichloride, followed by conjugation to an amine-functionalized tetraphenyl-porphyrin via an amide linkage. 相似文献
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Cross sections for (n, 2n), (n, p), (n, α) and [(n, n′p) + (n, pn)] reactions at 14.7 ± 0.3MeV on enriched 180, 182, 183, 184, 186W isotopes have been measured by the activation technique using Ge(Li) detector γ-ray spectroscopy. Some systematic trends in the cross-section data have been analysed. The (n, 2n) reaction at this energy in this mass region is by far the most favoured reaction and accounts for > 80 % of the total inelastic cross section. 相似文献
37.
De Napoli M Nardis S Paolesse R Vicente MG Lauceri R Purrello R 《Journal of the American Chemical Society》2004,126(19):5934-5935
In aqueous solution meso-tetrakis(4-phosphonatophenyl)porphyrin shows self-aggregation processes controlled by the "sergeant-soldier rule". After partial protonation of the external phosphonic groups, it is possible (i) to further protonate the inner nitrogen atoms of the molecules or (ii) to allow, over time, the system to aggregate. Therefore, the two procedure lead to a different system evolution, producing species with different chemico-physical properties. 相似文献
38.
Localization and photodynamic efficacy of two cationic porphyrins varying in charge distributions 总被引:1,自引:0,他引:1
Two meso-tetraphenylporphyrin derivatives bearing adjacent: 5,10-di[4-(N-trimethylaminophenyl)-15,20-diphenylporphyrin (DADP-a) or opposite: 5,15-di[4-(N-trimethylaminophenyl)-10,20-diphenylporphyrin (DADP-o) cationic-N-(CH3)3+ groups on two of the para-phenyl positions were examined with regard to photodynamic properties as a function of charge distribution. The two adjacent positive charges in the DADP-a structure result in a molecular distortion (asymmetry), likely from electrostatic repulsion. This could be responsible for the unusual interaction of this compound with some solvents and detergent micelles. In contrast, DADP-o is a much more symmetric molecule. In a cellular environment, fluorescence spectra of the two agents were essentially identical. Subcellular localization played a major role in photodynamic efficacy. DADP-a localized in mitochondria, and irradiation of photosensitized cells (640-650 nm) resulted in a rapid loss of the mitochondrial membrane potential (delta(psi)m), usually a prelude to apoptotic cell death. In contrast, DADP-o localized in lysosomes, and extensive lysosomal photodamage was observed after irradiation. Both steady-state accumulation levels and absorbance spectra favored DADP-o, but the light dose required for a 90% cell kill was two-fold greater for DADP-o than for DADP-a, at a constant extracellular sensitizer concentration. These data indicate that, on a photons/cell basis, DADP-a was five-fold more efficacious. Fluorescence emission spectra in different solvents and detergents demonstrated a tendency for DADP-a association. We interpret these results to indicate partition of both drugs to membrane loci, with mitochondriabeing the more lethal site for photodamage. 相似文献
39.
Oxidation of dodeca-substituted porphyrin 1 in the presence of NaNO2/TFA and air afforded benzoylbiliverdin 3 in 77% yield; under similar conditions the Ni(II)-porphyrin 2 was mainly nitrated at a cyclohexenyl ring; key X-ray structures are presented. 相似文献
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