Molecular catalytic coal liquid conversion. Quarterly progress report, [January--March 1993

Abstract

Last quarter, substantial progress has been made in the two general tasks advanced in our research proposal. The first task consists of the development of molecular homogeneous catalysts that can be used in the hydrogenation of coal liquids and in coal conversion processes. The second task concerns the activation of dihydrogen by basic catalysts in homogeneous reaction systems. With regards to the first task, we have prepared two organometallic rhodium (1) catalysts. These are the dimer of dichloropentamethylcyclopentadienylrhodium, [RhCl{sub 2}(C{sub 5}Me{sub 5})], and the dimer of chloro(1,5-hexadiene)rhodium We have subsequently investigated the hydrogenation of various aromatic organic compounds using these organometallic reagents as catalysts. Results showed that both catalysts effected the hydrogenation of the aromatic portions of a wide range of organic compounds, including aromatic hydrocarbons and aromatic compounds containing the ether group, alkyl groups, amino and carbonyl groups. However, both compounds were totally ineffective in catalyzing the hydrogenation of sulfur-containing aromatic organic compounds. Nevertheless, both rhodium catalysts successfully catalyzed the hydrogenation of naphthalene even in the presence of the coal liquids. With regards to base-activated hydrogenation of organic compounds, we have found that hydroxide and alkoxide bases are capable of activating,dihydrogen, thereby leading to the hydrogenation of phenyl-substituted alkenes.more » More specifically, tetrabutylammonium hydroxide, potassium tert-butoxide and potassium phenoxide were successfully used to activate dihydrogen and induce the hydrogenation of trans-stilbene. Potassium tert-butoxide was found to be slightly more effective than the other two bases in accomplishing this chemistry.« less