نتایج جستجو برای: expanded porphyrins
تعداد نتایج: 64232 فیلتر نتایج به سال:
Electronic absorption, florescence excitation and AFM studies of selected homogeneous solutions and thin films of mesotetrakis (parahydroxyphenyl) porphyrin (THPP) (1), mesotetrakis (2, 3- dihydroxyphenyl) porphyrin 2, 3-OHPP) (2), mesotetrakis (3, 4-dihydroxyphenyl) porphyrin (3, 4-OHPP) (3) as well as Zn(II) derivative of 2, 3-OHPP (4) under UV lamp and green laser irradiation (532 nm) are ac...
5-(4-X-Phenyl)-10,15,20-tris(substituted phenyl) porphyrins (4-6) were synthesized from meso-(substituted phenyl) dipyrromethanes (1-3), which in turn were prepared in yields of 75-92 %. This synthetic pathway was compared with the binary mixed aldehyde and pyrrole condensation method. The reported dipyrromethane approach is advantageous for porphyrins substituted by –OCH3 (4) and -F (6) groups...
Introduction Porphyrins are the extroverts of chemistry. Bright purple and fluorescent, they are used biologically in the processes of energy capture and utilization. Porphyrins are the key to life. It has been suggested that abiotic formation of porphyrins, in particular uroporphyrinogen would have provided the first pigments necessary for the eventual synthesis of the chlorophylls. This would...
We have firstly demonstrated the dual facet of gold(III) in the reaction between gold(III) and porphyrins, which could be tuned through changing the counter ions, ligands and the electronic effect of the substituents of the porphyrins.
Autism spectrum disorders (ASDs) may result from a combination of genetic/biochemical susceptibilities in the form of a reduced ability to excrete mercury and/or increased environmental exposure at key developmental times. Urinary porphyrins and transsulfuration metabolites in participants diagnosed with an ASD were examined. A prospective, blinded study was undertaken to evaluate a cohort of 2...
The syntheses, UV-VIS and fluorescence data of two methylbenzoate derivatives of tetrabenzoporphyrins, i.e., 5-p-methoxycarbonylphenyltetrabenzoporphyrin (TBPPhCO2Me), 5-p-methoxycarbonylphenyl-10,15,20triphenyltetrabenzoporphyrin (TPTBPCO2Me), and their zinc and magnesium complexes are described. The latter was tested as a bis(zinc-porphyrin) host in the CD-based molecular recognition studies ...
1. Iron protoporphyrin IX was required for the growth of H. influenzae. It could be replaced by protoporphyrin IX. When grown on protoporphyrin evidence was obtained for the presence of Fe porphyrin in the organism. It was concluded that the organism could insert iron into the protoporphyrin ring. 2. In the smooth strains, other porphyrins containing no iron such as deutero-, hemato-, meso-, an...
In the review hybrids of cationic porphyrins (i.e. porphyrins functionalized by quaternary pyridinium groups) with nanocarbons such as fullerenes, carbon nanotubes and graphene are described. Selected examples of these species are characterized in regard of their properties and possible applications.
The structural chemistry of the blood and bile pigments has been developed by Hans Fischer and his school (l), but the physiological conditions which lead to the increased production of these pigments, especially of the porphyrins, are still uncertain. Although it is well known that in many diseases, notably those characterized by fever or liver injury (2), an increased excretion of porphyrins ...
A series of free base meso-tetraarylporphyrins functionalized with substituents containing one, two, and four cyclooctatetraene (COT) moieties have been obtained characterized by spectral photophysical studies. Three COT-free porphyrins served as reference compounds. COT is a triplet quencher, well-known to enhance the photostability several, but not all, fluorophores. In case porphyrins, subst...
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