Resonance stabilisation of zinc porphyrin π-radical cations

1986 ◽  
Vol 82 (2) ◽  
pp. 209-217 ◽  
Author(s):  
Pedatsur Neta ◽  
Marie-Claude Richoux ◽  
Anthony Harriman ◽  
Lionel R. Milgrom
Keyword(s):  
Radical Cations ◽  
Zinc Porphyrin

ChemInform Abstract: Iridium Oxide Hydrosols as Catalysts for the Decay of Zinc Porphyrin Radical Cations in Water.

ChemInform ◽  
1988 ◽  
Vol 19 (45) ◽  
Author(s):  
A. HARRIMAN ◽  
G. S. NAHOR ◽  
S. MOSSERI ◽  
P. NETA
Keyword(s):  
Radical Cations ◽  
Iridium Oxide ◽  
Zinc Porphyrin

scholarly journals Simultaneous Occurrence of Three Different Valence Tautomers in meso-Vinylruthenium-Modified Zinc Porphyrin Radical Cations

2013 ◽  
Vol 135 (9) ◽  
pp. 3391-3394 ◽  
Author(s):  
Jing Chen ◽  
Evelyn Wuttke ◽  
Walther Polit ◽  
Thomas Exner ◽  
Rainer F. Winter
Keyword(s):  
Radical Cations ◽  
Simultaneous Occurrence ◽  
Zinc Porphyrin ◽  
Valence Tautomers

Fast self-exchange electron transfer and delocalization of unpaired electron between zinc porphyrin radical cations and zinc porphyrins

2003 ◽  
Vol 07 (05) ◽  
pp. 328-336 ◽  
Author(s):  
Shunichi Fukuzumi ◽  
Taku Hasobe ◽  
Yoshito Endo ◽  
Kei Ohkubo ◽  
Hiroshi Imahori
Keyword(s):  
Electron Transfer ◽  
Radical Cation ◽  
Unpaired Electron ◽  
Radical Cations ◽  
Esr Spectra ◽  
The Self ◽  
Fine Tuning ◽  
Transfer Rates ◽  
Zinc Porphyrin ◽  
Zinc Porphyrins

Self-exchange electron transfer rates between π-radical cations of zinc porphyrins and the neutral metalloporphyrins have been determined from the line-width broadening in the ESR spectra in different solvents at various temperatures. Fine tuning of the substituent on the porphyrin ring and the proper choice of the solvent have enabled us to observe negative activation enthalpies for the self-exchange electron transfer reactions. The observation of negative activation enthalpies indicates that the self-exchange electron transfer occurs via the charge-transfer π-complexes formed between zinc porphyrin radical cations and the neutral zinc porphyrins. The complete delocalization of the unpaired electron over two porphyrin moieties is observed in the radical cation of a zinc porphyrin dimer, 5,5'-bis(10,20-bis(3,5-di-tert-butylphenyl)porphyrinatozinc(II)). This is regarded as the extreme limit of the rapid self-exchange electron transfer between zinc porphyrin radical cation and the neutral form.

Reactivity Trends in the Gas Phase Addition of Acetylene to N-protonated Aryl Radical Cations

2020 ◽  
Author(s):  
Oisin Shiels ◽  
P. D. Kelly ◽  
Cameron C. Bright ◽  
Berwyck L. J. Poad ◽  
Stephen Blanksby ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ion Trap ◽  
Radical Cations ◽  
Rate Coefficients ◽  
Similar Process ◽  
Ion Molecule Reactions ◽  
Aromatic Radicals ◽  
Polycyclic Aromatic ◽  
Gas Phase Ion ◽  
Type Radical

<div> <div> <div> <p>A key step in gas-phase polycyclic aromatic hydrocarbon (PAH) formation involves the addition of acetylene (or other alkyne) to σ-type aromatic radicals, with successive additions yielding more complex PAHs. A similar process can happen for N- containing aromatics. In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged. This paper investigates the gas-phase ion-molecule reactions of acetylene with nine aromatic distonic σ-type radical cations derived from pyridinium (Pyr), anilinium (Anl) and benzonitrilium (Bzn) ions. Three isomers are studied in each case (radical sites at the ortho, meta and para positions). Using a room temperature ion trap, second-order rate coefficients, product branching ratios and reaction efficiencies are reported. </p> </div> </div> </div>

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

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