adj-Dicarbachlorin, the first free base carbaporphyrinoid system with an internal methylene unit

2015 ◽  
Vol 51 (88) ◽  
pp. 15952-15955 ◽  
Author(s):  
Timothy D. Lash ◽  
Deyaa I. AbuSalim ◽  
Gregory M. Ferrence
Keyword(s):  
Free Base ◽  
Methylene Unit

Base-catalyzed condensation of dicyclopentadienylmethane with a dipyrrylmethane dialdehyde gave a dicarbachlorin with an internal CH2 group.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

Free‐base tetra‐arylphthalocyanines for dye‐sensitised nanostructured solar cell applications

2001 ◽  
Vol 5 (8) ◽  
pp. 609-616 ◽  
Author(s):  
Viviane Aranyos ◽  
Johan Hjelm ◽  
Anders Hagfeldt ◽  
Helena Grennberg
Keyword(s):  
Solar Cell ◽  
Free Base

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

Photophysical Properties of β-Substituted Free-Base Corroles

2015 ◽  
Vol 54 (6) ◽  
pp. 2713-2725 ◽  
Author(s):  
Christopher M. Lemon ◽  
Robert L. Halbach ◽  
Michael Huynh ◽  
Daniel G. Nocera
Keyword(s):  
Photophysical Properties ◽  
Free Base

The lowest triplet state of free base porphin

1975 ◽  
Vol 30 (6) ◽  
pp. 1701-1721 ◽  
Author(s):  
W.G. van Dorp ◽  
W.H. Schoemaker ◽  
M. Soma ◽  
J.H. van der Waals
Keyword(s):  
Triplet State ◽  
Free Base

Synthesis and Photophysical Properties of a Conformationally Flexible Mixed Porphyrin Star-Pentamer

2009 ◽  
Vol 62 (7) ◽  
pp. 692 ◽  
Author(s):  
Toby D. M. Bell ◽  
Sheshanath V. Bhosale ◽  
Kenneth P. Ghiggino ◽  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Fluorescence Decay ◽  
High Yield ◽  
Free Base ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Relative Contribution ◽  
Synthetic Strategy ◽  
Decay Times

The synthesis of a porphyrin star-pentamer bearing a free-base porphyrin core and four zinc(ii) metalloporphyrins, which are tethered by a conformationally flexible linker about the central porphyrin’s antipody, is described. The synthetic strategy is highlighted by the use of olefin cross metathesis to link the five chromophores together in a directed fashion in high yield. Photoexcitation into the Soret absorption band of the zinc porphyrin chromophores at 425 nm leads to a substantial enhancement of central free-base porphyrin fluorescence, indicating energy transfer from the photoexcited zinc porphyrin (outer periphery) to central free-base porphyrin. Time-resolved fluorescence decay profiles required three exponential decay components for satisfactory fitting. These are attributed to emission from the central free-base porphyrin and to two different rates of energy transfer from the zinc porphyrins to the free-base porphyrin. The faster of these decay components equates to an energy-transfer rate constant of 3.7 × 109 s–1 and an efficiency of 83%, whereas the other is essentially unquenched with respect to reported values for zinc porphyrin fluorescence decay times. The relative contribution of these two components to the initial fluorescence decay is ~3:2, similar to the 5:4 ratio of cis and trans geometric isomers present in the pentamer.

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