Depolymerization mechanism of model coal linkages: Final report

Technical Report · Tue Dec 01 04:00:00 EST 1987

OSTI ID:5466677

Fish, R

Depolymerization of coal, by the use of chemical reducing agents such as alkali metals in amine or ether solvents as well as in the presence of the alkali cation binding crown ethers, has resulted in considerable speculation concerning the reactivity of coal linkages. The objective of this project is to develop a fundamental understanding of the mechanistic chemistry associated with aromatic esters and ethers, which are models for several coal linkages, in their reactions with solvated electrons. Results show that aromatic esters, substituted with methoxyl and hydroxyl groups, react upon mixing with the electron-transfer reagent K metal / 18-Crown-6 / THF, at 0/sup 0/C. The methoxy substituted ethers, which were slower than the corresponding esters, did not show any pronounced rate differences when compared to the standard, diphenyl ether. The regioselectivity for C-O bond-cleavage was found to be at the carbonyl-oxygen bond for all the aromatic esters studied. The 4-substituted aromatic ether cleavage reactions led to the 4-substituted phenols; however, the exception was the 2-methoxyphenyl phenyl ether, which provided phenol. The effect of the substituents on the relative rate of C-O bond-cleavage for the aromatic esters and ethers was briefly studied by a qualitative Hammett treatment. 24 refs., 4 figs., 2 tabs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5466677
• Report Number(s): EPRI-ER-5474; ON: DE88004265
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKALI METALS
AMINES
AROMATICS
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMICAL REACTORS
CHEMICAL STATE
CLEAVAGE
COAL
COAL LIQUEFACTION
COAL RANK
COMPARATIVE EVALUATIONS
CRYSTAL STRUCTURE
DECOMPOSITION
DEPOLYMERIZATION
ELECTRON TRANSFER
ELEMENTS
ENERGY SOURCES
ESTERS
ETHERS
FOSSIL FUELS
FUELS
FURANS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
KINETICS
LIQUEFACTION
MATERIALS
METALS
MICROSTRUCTURE
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
POTASSIUM
REACTION INTERMEDIATES
REACTION KINETICS
REDUCING AGENTS
REDUCTION
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
TETRAHYDROFURAN
THERMOCHEMICAL PROCESSES