نتایج جستجو برای: porphyrin
تعداد نتایج: 6995 فیلتر نتایج به سال:
Removal of the heme iron from cytochrome c to generate porphyrin cytochrome c relieves the quenching of porphyrin fluorescence and enhances the fluorescence of the single tryptophan residue and the 4 tyrosine residues. The intensity of the porphyrin fluorescence is not perturbed by denaturation of the protein at neutral pH using either urea or guanidine hydrochloride. However, the amplitude of ...
We have employed water-soluble porphyrin molecules [meso-(tetrakis-4-sulfonatophenyl) porphine dihydrochloride] to solubilize single-walled carbon nanotubes (SWNTs), resulting in aqueous solutions that are stable for several weeks. The porphyrin-nanotube complexes have been characterized with absorption and fluorescence spectroscopy and with AFM. We find that the porphyrin/SWNT interaction is s...
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX)....
Page 32 Howard University Abstract: The kinetics of Zn metal incorporation into porphyrin encapsulated phosphatidylcholine (PC) vesicles (or liposomes) was studied using spectrophotometry. (Figure 1) Liposomes, made by controlled detergent dialysis, were characterized by multiangle static light scattering to prove that they were unilamellar and monodisperse in size. The average radius of the ve...
Recently, third-order nonlinear properties of porphyrins and porphyrin polymers and coordination compounds have been extensively studied in relation to their use in photomedicine and molecular photonics. A new functionalized porphyrin dye containing electron-rich alkynes was synthesized and further modified by formal [2+2] click reactions with click reagents tetracyanoethylene (TCNE) and 7, 7, ...
The synthesis and photophysical characterization of a palladium(II) porphyrin - anthracene dyad bridged via short and conformationally rigid bicyclo[2.2.2]octadiene spacer were achieved. A spectroscopic investigation of the prepared molecule in solution has been undertaken to study electronic energy transfer in excited singlet and triplet states between the anthracene and porphyrin units. By us...
Synthesis and spectral evaluation of new zinc and copper unsymmetrical mesoporphyrinic complexes are reported. Zn(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Zn(II)-5-[(3,4-methylenedioxy)phenyl]-10,15,20- tris-(4-carboxymethylphenyl)porphyrin, Cu(II)-5-(4-acetoxy-3-methoxyphenyl)-10,15,20- tris-(4-carboxymethylphenyl)porphyrin and Cu(II)-5-[(3,4-methylene...
In the title compound, C(48)H(38)N(4)O(8)·C(3)H(6)O(2), the porphyrin mol-ecule is centrosymmetric. The propionic acid solvent mol-ecule is disordered over two sets of sites with equal occupancy factors. The porphyrin central core is almost planar, with an r.m.s. deviation of the fitted atoms of 0.045 Å. The substituent benzene rings make dihedral angles of 70.37 (4) and 66.95 (4)° with respect...
The present study (see ref 1) delineates the scope and limitations of porphyrin chromophores for structural studies by the exciton coupled circular dichroic (CD) method. A distance dependency of the porphyrin coupling was investigated in the range between 10 and 50 Å. Over short interchromophoric distances, significant changes in the conformational distribution introduced by the bulky porphyrin...
A zinc porphyrin derivative (2) and zinc porphyrin-bodipy dyad (3) have been prepared and applied to dye-sensitized solar cells (DSSCs). On the basis of absorption and fluorescence excitation spectra, dyad 3 efficiently transfers energy from the bodipy to zinc porphyrin constituent. The 3-sensitized solar cell demonstrates higher solar spectral coverage, based on incident photon to current effi...
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