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Porphyrin-chlorin

All other methods for obtaining bacteriochlorins are by partial synthesis from porphyrins, chlorins or chlorin derivatives. The bacteriochlorin is thereby produced by reactions which occur at the peripheral /J-C — C double bonds of the higher unsaturated systems. The main problem of these syntheses is the lack of regio- and stereoselectivity because three or four C —C double bonds, which are present in the starting products may be attacked, so that rcgio-and stcreoisomcric products can be formed. [Pg.637]

Whereas in porphyrins, chlorins and bacteriochlorins the 1871-aromatic perimeter includes two nitrogens excluding their lone pairs, the.1871 perimeter of the isobacteriochlorin includes three nitrogens, one with its electron lone pair as part of the aromatic perimeter. The electron pair of the /J,/J -C —C double bond of ring D of isobacteriochlorin is not involved in the cyclic conjugation path. [Pg.644]

Chemical analysis revealed that commercial food grade copper chlorophyllin is not a single, pure compound, but is a complex mixture of structurally distinct porphyrins, chlorin, and non-chlorin compounds with variable numbers of mono-, di-, and tri- carboxylic acid that may be present as either sodium or potassium salts. Although the composition of different chlorophyllin mixtures may vary, two compounds are commonly found in commercial chlorophyllin mixtures trisodium Cu (II) chlorin Cg and disodium Cu (II) chlorin which differ in the number of... [Pg.206]

Chu TC, Chu EJ. 1966. Thin-layer chromatography of methyl esters of porphyrins, chlorins, and related compounds with Eastman "chromagram." J Chromatogr 21(1) 46-51. [Pg.170]

Figure 24-21 Biosynthesis of porphyrins, chlorins, and related compounds. Figure 24-21 Biosynthesis of porphyrins, chlorins, and related compounds.
Geochemistry of Porphyrins, Chlorins and Polycyclic Aromatics in Soils, Sediments and Sedimentary Rocks, Geochim. Cosmochim. Acta (1968) 32 (7), 737-772. [Pg.61]

It is easier for intermolecular interactions to occur in the case of M3+ correlates than in analogous complexes with porphyrins, chlorins or phthalo-... [Pg.95]

The present article reviews the photochemical deactivation modes and properties of electronically excited metallotetrapyrroles. Of the wide variety of complexes possessing a tetrapyrrole ligand and their highly structured systems, the subject of this survey is mainly synthetic complexes of porphyrins, chlorins, corrins, phthalocyanines, and naphthalocyanines. All known types of photochemical reactions of excited metallotetrapyrroles are classified. As criteria for the classification, both the nature of the primary photochemical step and the net overall chemical change, are taken. Each of the classes is exemplified by several recent results, and discussed. The data on exciplex and excimer formation processes involving excited metallotetrapyrroles are included. Various branches of practical utilization of the photochemical and photophysical properties of tetrapyrrole complexes are shown. Motives for further development and perspectives in photochemistry of metallotetrapyrroles are evaluated. [Pg.135]

Another important characteristic of photoreactive agents is their apparent affinity for certain targets that are of special interest for interventional vascular therapists, As most photosensitizers fluoresce, the kinetics of their distribution in vascular tissue can be investigated both at macroscopic and microscopic levels using fluorescence imaging techniques (Fig, 3), Numerous studies on porphyrin, chlorin, texaphryin, pheophorbide and phthalocyanine photosensitizers in various animal models have documented selective localization in... [Pg.383]

MO calculations for simple porphyrins, chlorins, and bacteri-ochlorins show that, within the same series, the LUMOs are nearly isoenergetic, that is, they do not change as the number of n electrons is reduced from 22 to 20 and to 18 along the series. However, the increased Z)2h skeletal distortion destabilizes the HOMOs, and their energies increase systematically (Fig. 3 (10)). [Pg.192]

Battersby AR, McDonald E (1975) Biosynthesis of porphyrins, chlorins and corrins. In Smith KM (ed) Porphyrins and metalloporphyrins. Elsevier, Amsterdam, p 61... [Pg.189]

In the conventional applications of photodynamic therapy (PDT), fight-activated chemicals (photosensitizers) are used to destroy fast-growing cells and tissues. The commonly used sensitizers are based upon porphyrin-like molecules, e.g., porphyrins, chlorins, bacteriocholins, and phthalocyanines. These substances collect in... [Pg.342]

Redox chemistry of nickel(II) hydroporphyrins has gained importance because of its biological significance. F430 involves both Ni(II) and Ni(I) during catalytic cycle for the conversion of C02 to methane. The redox chemistry performed on various Ni(II) hydroporphyrin systems concludes that the reduction of only Ni(II) F43o and isobacteriochlorins unambiguously results in Ni(I) species whereas porphyrins, chlorins, hexahydro- and octahydro-porphyrins yield anions variously ascribed to Ni(I) or Ni(II) 7t-radicals with some metal character [96],... [Pg.124]


See other pages where Porphyrin-chlorin is mentioned: [Pg.615]    [Pg.626]    [Pg.637]    [Pg.1217]    [Pg.2]    [Pg.16]    [Pg.16]    [Pg.118]    [Pg.31]    [Pg.393]    [Pg.96]    [Pg.303]    [Pg.305]    [Pg.308]    [Pg.336]    [Pg.2099]    [Pg.2110]    [Pg.2138]    [Pg.2155]    [Pg.222]    [Pg.311]    [Pg.622]    [Pg.33]    [Pg.1145]    [Pg.37]    [Pg.184]    [Pg.191]    [Pg.118]    [Pg.125]    [Pg.49]    [Pg.54]    [Pg.330]    [Pg.2098]    [Pg.2109]   
See also in sourсe #XX -- [ Pg.393 ]




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