Radical anion of naphthalene

This technique is especially useful for the preparation of a-lithio ethers, sulfides, and silanes.36 The lithium radical anions of naphthalene, 4, 4/-di-f-butyldiphenyl (DTBB) or dimethylaminonaphthalene (LDMAN) are used as the reducing agent. 

Reduction of trichloroethylene by a series of well-characterized outer-sphere electron-transfer reagents, viz. the radical anions of naphthalene, pyrene, perylene, decamethylcobaltocene, and cobaltocene, resulted in the formation of cis- and trans-dichloroethylene in ratio varying from 0.87 to 4.5, whereas in the reduction by vitamin B12, the ratio was 30 1. This indicated that reduction with vitamin B12 occurs with a non-outer-sphere electron-transfer mechanism. A mechanism involving initial formation of a radical ion followed by an ejection of a chloride to give d.v-dichlorovinyl radical and franx-dichlorovinyl radical has been proposed.284... 

Johnson and Willson interpreted the main feature of the observations on solid polyethylene doped with aromatic solutes in terms of an ionic mechanism it was analogous to that proposed for irradiated frozen glassy-alkane-systems in which ionization occurred with G = 3 — 4 [96], The produced charged species, electron and positive hole, were both mobile as indicated by the radiation-induced conductivity. The production of excited states of aromatic solutes was caused mainly by ion-electron neutralization. The ion-ion recombination was relatively slow but it might contribute to the delayed fluorescence observed. On the basis of Debye-Simoluchovski equation, they evaluated the diffusion coefficients of the radical anion of naphthalene and pyrene as approximately 4 x 10 12 and 1 x 10 12 m2 s 1 respectively the values were about three orders of magnitude less than those found in typical liquid systems. 

With a redox potential of —3.10 V relative to FeCp2 in THF, the radical anion of naphthalene (NpH ) is, in theory, the most powerful reducing agent used (see the discussion above, however) ... 

The bond lengths in the radical anion of naphthalene are probably intermediate between those of the naphthalene dianion and the naphthalene molecule. The lower-energy angular distortions of the molecule from planarity may however be similar in the radical and dianion species. 

Thus, the radical anion of naphthalene reacted differently with methyl iodide (to form methyl radicals) than with pentyl iodide (to undergo substitution). Perylene, on the other hand, underwent substitution with methyl iodide whether or not naphthalene was present perylene also underwent substitution with pentyl iodide when naphthalene was present. 

Curiously, in reacting with methyl iodide so readily to make dimethyl dihydro products, the perylene dianion is distinct from the radical anion of naphthalene, which primarily reduces methyl iodide to the methyl radical and the iodide anion. 

The disproportionation [reaction (19)] of lithium salts of radical anions of naphthalene, anthracene, tetracene, perylene, and pyrene in Et20 and of sodium tetracenide in has been investigated. The magnitudes of the... 

Radicals may also result from chemical or electrochemical oxidation or reduction of stable molecules. Single-electron transfer processes initially generate radical cations (for oxidation) or radical anions (for reduction), which may then fragment to radicals and ions. For example, Sargent and coworkers determined that in 1,2-dimethoxyethane solutions the radical anion of naphthalene (sodium naph-thalenide, Na" " Ar ) transferred an electron to propyl iodide. Subsequent loss of... 

The lithium radical anion of naphthalene or dimethylaminonaphthalene (LDMAN) is used as the reducing agent. This method can also be applied to prepare unsub-... 

Figure 6 EPR spectrum of the radical anion of naphthalene in tetrahydrofuran as solvent. The radical was formed by dissolving naphthalene in sodium-dried tetrahydrofuran under vacuum and passing the resultant solution over a sodium metal film, again under vacuum conditions. The number of lines is given by 2nl+ I where / equals the nuclear spin and n the number of nuclei. HFCC for 1,4,5,8 = 0.483 mT and for 2,3,6,7 = 0.185 mT.

---