Crystal structure of the radical-cation radical-anion salt from 2,2′-bi-1,3-dithiole and 7,7,8,8-tetracyanoquinodimethane

1973 ◽  
pp. 471-472 ◽  
Author(s):  
Terry E. Phillips ◽  
Thomas J. Kistenmacher ◽  
John P. Ferraris ◽  
Dwaine O. Cowan
Keyword(s):  
Crystal Structure ◽  
Radical Cation ◽  
Radical Anion ◽  
Cation Radical

Radical cation-radical anion salts: Molybdenum complexes containing the [TCNQ]•− or [TCNE]•− radical anions. X-ray crystal structure of [Mo(Et2NCS2)4](TCNQ)

Polyhedron ◽  
1995 ◽  
Vol 14 (13-14) ◽  
pp. 1741-1750 ◽  
Author(s):  
M. Decoster ◽  
F. Conan ◽  
J.E. Guerchais ◽  
Y. Le Mest ◽  
J. Sala Pala ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Radical Cation ◽  
Radical Anion ◽  
Cation Radical ◽  
Radical Anions ◽  
Molybdenum Complexes ◽  
X Ray

A Fluorine 1,2-Migration via Aryl Cation/Radical/Radical Anion/Radical Sequence

2013 ◽  
Vol 15 (15) ◽  
pp. 3926-3929 ◽  
Author(s):  
Luca Pretali ◽  
Daniele Dondi ◽  
Mila D’Angelantonio ◽  
Ilse Manet ◽  
Elisa Fasani ◽  
...  
Keyword(s):  
Radical Anion ◽  
Anion Radical ◽  
Cation Radical

scholarly journals Disorder of the dimeric TCNQ–TCNQ unit in the crystal structure of [Ni(bpy)3]2(TCNQ–TCNQ)(TCNQ)2·6H2O (TCNQ is 7,7,8,8-tetracyanoquinodimethane)

2017 ◽  
Vol 73 (1) ◽  
pp. 8-12
Author(s):  
Juraj Černák ◽  
Juraj Kuchár ◽  
Michal Hegedüs
Keyword(s):  
Crystal Structure ◽  
Radical Anion ◽  
Title Complex ◽  
Molar Ratio ◽  
Water Molecules ◽  
Aqueous Methanol ◽  
Solvent Water ◽  
Hydrogen Bonding Interactions ◽  
Methanol System ◽  
Anion Radicals

Crystallization from an aqueous methanol system composed of Ni(NO3)2, 2,2′-bipyridine (bpy) and LiTCNQ (TCNQ is 7,7,8,8-tetracyanoquinodimethane) in a 1:3:2 molar ratio yielded single crystals of bis[tris(2,2′-bipyridine-κ2N,N′)nickel(II)] bis(7,7,8,8-tetracyanoquinodimethane radical anion) bi[7,7,8,8-tetracyanoquinodimethanide] hexahydrate, [Ni(C10H8N2)3]2(C24H8N8)(C12H4N4)2·6H2O or [Ni(bpy)3]2(TCNQ–TCNQ)(TCNQ)2·6H2O. The crystal structure comprises [Ni(bpy)3]2+complex cations, two centrosymmetric crystallographically independent TCNQ·−anion radicals with π-stacked exo groups, and an additional dimeric TCNQ–TCNQ unit which comprises 75.3 (9)% of a σ-dimerized (TCNQ–TCNQ)2−dianion and 24.7 (9)% of two TCNQ·−anion radicals with tightly π-stacked exo groups. The title complex represents the first example of an NiIIcomplex containing a σ-dimerized (TCNQ–TCNQ)2−dianion. Disordered solvent water molecules present in the crystal structure participate in hydrogen-bonding interactions.

Radical ions in photochemistry. 21. The photosensitized (electron transfer) tautomerization of alkenes; the phenyl alkene system

1989 ◽  
Vol 67 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Donald R. Arnold ◽  
Shelley A. Mines
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Radical Cation ◽  
Radical Anion ◽  
Phenyl Group ◽  
Oxidation Potential ◽  
Original Position ◽  
Acetonitrile Solution ◽  
Steric Interaction ◽  
Ambident Anion

Alkenes, conjugated with a phenyl group, can be converted to nonconjugated tautomers by sensitized (electron transfer) irradiation. For example, irradiation of an acetonitrile solution of the conjugated alkene 1-phenylpropene, the electron accepting photosensitizer 1,4-dicyanobenzene, the cosensitizer biphenyl, and the base 2,4,6-trimethylpyridine gave the nonconjugated tautomer 3-phenylpropene in good yield. Similarly, 2-methyl-1-phenylpropene gave 2-methyl-3-phenylpropene, and 1-phenyl-1-butene gaveE- and Z-1-phenyl-2-butene. The reaction also works well with cyclic alkenes. For example, 1-phenylcyclohexene gave 3-phenylcyclohexene, and 1-(phenylmethylene)cyclohexane gave 1-(phenylmethyl)cyclohexene. The proposed mechanism involves the initial formation of the alkene radical cation and the sensitizer radical anion, induced by irradiation of the sensitizer and mediated by the cosensitizer. Deprotonation of the radical cation assisted by the base gives the ambident radical, which is then reduced to the anion by the sensitizer radical anion. Protonation of the ambident anion at the benzylic position completes the sequence. Reprotonation at the original position is an energy wasting step. Tautomerization is driven toward the isomer with the higher oxidation potential, which is, in the cases studied, the less thermodynamically stable isomer. The regioselectivity of the deprotonation step is dependent upon the conformation of the allylic carbon–hydrogen bond. The tautomerization of 2-methyl- 1-phenylbutene gave both 2-phenylmethyl-1-butène and 2-methyl-1-phenyl-2-butene (E and Z isomers), while 2,3-dimethyl- 1-phenylbutene gave only 3-methyl-2-phenylmethyl-1 -butene. In the latter case, steric interaction of the methyls on the isopropyl group prevents effective overlap of the tertiary carbon–hydrogen bond with the singly occupied molecular orbital, thus inhibiting deprotonation from this site. Keywords: photosensitized, electron transfer, alkene, tautomerization, radical cation.

Spectroscopy of Free-Base N-Confused Tetraphenylporphyrin Radical Anion and Radical Cation

2011 ◽  
Vol 115 (24) ◽  
pp. 6456-6471 ◽  
Author(s):  
Elvin A. Alemán ◽  
Juan Manríquez Rocha ◽  
Wongwit Wongwitwichote ◽  
Luis Arturo Godínez Mora-Tovar ◽  
David A. Modarelli
Keyword(s):  
Radical Cation ◽  
Radical Anion ◽  
Free Base
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