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The single electron chemistry of coals

Description: TCNQ Charge Transfer Complexes with Coals. TCNQ can be readily deposited in coals from pyridine solution. IR spectra of TCNQ and TCNQ in Illinois No. 6 coal are shown in Fig. 1. It is clear that the stretching frequency has been shifted by the full 44 cm[sup [minus]1] caused by the transfer of a single electron. Similar behavior has been observed with a variety of coals, including lignites, subbituminous and a range of bituminous coals. There are two possible explanations for the observed shift… more
Date: July 24, 1990
Creator: Larsen, John W. & Flowers, Robert A., II.
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. [Quarterly] report, January 1, 1991--March 31, 1991

Description: The simplest explanation for these shifts in the infrared spectra is there exists in coal single electron donors which are capable of transferring an electron to TCNQ in the ground state. All of the TCNQ placed in the coal appears to be converted to the radical anion as displayed in the IR spectrum for all of the coals except for the 100% loading.
Date: April 22, 1991
Creator: Larsen, John W. & Flowers, Robert A., II
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. [Quarterly] report, July 1, 1990--December 30, 1990

Description: Our work on single election transfer in coals led us to the knowledge that the energetics of bond cleavage in radical cations is 20-40 kcal/mole lower than the corresponding homolytic bond cleavage energies. Having made excellent progress in the other areas covered by this proposal, we are extending our studies to the investigation of the formation and cleavage reaction of radical cations in coals. The formation of a radical cation requires the transfer of an electron from a neutral molecule to… more
Date: January 18, 1991
Creator: Larsen, John W. & Kaushal, P.
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. [Quarterly] report, January 1--March 31, 1993

Description: Following the position of the nitrile band and using the assumption that there is a linear relationship for between the extent of charge transfer and frequency, a 69% charge transfer was obtained and successfully replicates Flowers` results. If a Diels-Alder reaction occurred, we would expect the position of nitrile group to have shifted down field to the 2260-2240 cm{sup {minus}1} range for a saturated alkyl nitrile. There is no evidence for this type of reaction under these conditions since w… more
Date: September 1, 1993
Creator: Larsen, John W. & Rothenberg, S. E.
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. Quarterly report, October 1, 1993--December 31, 1993

Description: The objective of this work is to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. The work here is concerned with the interactions of coals, such as Illinois No. 6, with tetracyanoethylene.
Date: August 1, 1994
Creator: Larsen, John W. & Rothenberg, S. E.
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. [Quarterly] report, July 1--September 30, 1993

Description: Tetracyanoethylene (TCNE) and Tetracyanoquinodimethane (TCNQ) were used earlier in an attempt to determine the single electron donating ability of aromatic groups in coals. The extent of electron transfer from coals to these compounds was measured by determining the frequency shift of the nitrile stretching bands in the Diffuse Reflectance (DR) infrared spectra. Our addition to this work will be to study the interactions of coals, such as Illinois No. 6, with TCNE. We will determine whether a D… more
Date: December 31, 1993
Creator: Larsen, John W. & Rothenberg, S. E.
Partner: UNT Libraries Government Documents Department
open access

The single electron chemistry of coals

Description: Our work on single election transfer in coals led us to the knowledge that the energetics of bond cleavage in radical cations is 20-40 kcal/mole lower than the corresponding homolytic bond cleavage energies. Having made excellent progress in the other areas covered by this proposal, we are extending our studies to the investigation of the formation and cleavage reaction of radical cations in coals. The formation of a radical cation requires the transfer of an electron from a neutral molecule to… more
Date: January 18, 1991
Creator: Larsen, J. W. & Kaushal, P.
Partner: UNT Libraries Government Documents Department
open access

The single electron chemistry of coals. [Quarterly], April 1--June 30, 1992

Description: Depolymerization of coals at low temperatures may offer advantages over thermal bond cleavage. Because bond cleavage energies of radical cations are lower than the corresponding homolytic bond cleavage energies of the same bond, generation of radical cations in coal may make possible depolymerization at lower temperatures. We seek to investigate the above possibility using single molecules containing functional groups common in coals. Since the generation of a radical cation requires the remova… more
Date: October 1, 1992
Creator: Larsen, John W. & Eskay, T. P.
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals, January 1, 1990--March 30, 1990

Description: The Wyodak, Upper Freeport and Pocahontas No. 3 samples containing DPPD display a decrease in spin density as compared to the starting coals. Coincident with this decrease is a loss or decrease of the narrow inertinite signal in the esr spectrum of these coals. The Pittsburgh No. 8 coal sample containing DPPD also displays a loss of spin density as compared to the starting coal but there is no change in the esr spectrum. These results compare well with earlier work involving 4-vinylpyridine and… more
Date: April 16, 1990
Creator: Larsen, John W. & Flowers, Robert A., II
Partner: UNT Libraries Government Documents Department
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The single electron chemistry of coals. [Quarterly] report, October 1--December 31, 1992

Description: Radical cation generation in coal may make possible depolymerization at low temperature. This possibility was investigated using single molecules containing functional groups common in coals. Single- electron oxidations of 4,4{prime}-dimethoxybibenzyl (DMBB) by Fe(III) (1,10-phenanthroline){sub 3}(ClO{sub 4}){sub 3}, in refluxing CH{sub 3}CN, gave incomplete mass balances; an attempt was made to identify the additional products. Part of these products were deduced to be dimer, p-methoxybenzylat… more
Date: December 31, 1992
Creator: Larsen, John W. & Eskay, T. P.
Partner: UNT Libraries Government Documents Department
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