Reductive ethylation in ethereal solvents

Organic compounds, in particular anthracene and naphthalene, and two coals have been reductively ethylated in tetrahydrofuran (THF) and diglyme using alkali metals to form anions and ethyl iodide to produce ethylates. Product distributions were sensitive to experimental conditions. The rate of anion formation was controlled by their rate of desorption, probably as contact ion pairs, from the alkali metal surface. The enthalpy of formation of a solvated contact ion pair was ?500 kJ mole-1 mainly due to dipole-solvent interaction. 18-crown-6 ether was used to diagnose that, when treated with potassium in THF, anthracepe gave solvated contact ion pairs and probably di-anions whose reactions were characterized by the formation of ethyldihydroanthracene. Naphthalene under identical conditions gave loosely solvated mono-anions which reacted by electron transfer to give diethyldihydronaphthalene. With other alkali metals anthracene and naphthalene gave similar product distributions. The behaviour of other polynuclear aromatic hydrocarbons and of two coals was classified in the same way. It is suggested that when coals are readily solubilized by reductive alkylation mono-alkyldihydro products will predominate. © 1984.Connecticut State Emergency Response CommissionA~KNOWLED~E~E~S The authorsa reg ratefult o N. Owen for hisc onstanth elp. 0. Erbaturh asr eceivedg enerouss upportf rom theB ritish Council and the OverseasD eveIopmentA dministration. The work formsp art of a project,‘ The Chemistryo f Solid Fuels’ supportedb y the SERC

Infrared spectra of humodetrinite from the Fortuna-Garsdorf mine

The infrared spectra of four samples of soft brown coal of Miocene age which varied systematically both in colour and in attrinite:densinite ratio have been determined. The spectra of the coals were very similar to each other as were those of the coals which had been benzoylated or acetylated and this suggests that the chemical structures of attrinite and densinite must be similar and that little difference exists between the lithotypes. © 1981.North Atlantic Treaty OrganizationThe remission measurements,t he maceral analyses, the proximate and ultimate analyses recorded in Table 1 were carried out by Erik Thomsen (Aarhus, Denmark) to whom the authors are sincerely grateful. The work forms part of an investigation of the geochemistry of lignite directed by Professor Dr G. Ataman and supported by NATO funds for international scientific cooperation

ON THE MECHANISM OF REDUCTIVE ALKYLATION OF AROMATIC COMPOUNDS IN ETHEREAL SOLVENTS.

Int Energy Agency, Paris, FrProceedings - 1985 International Conference on Coal Science. -- -- Sydney, Aust --Naphthalene and anthracene were reductively alkylated in tetrahydrofuran and diglyme using potassium to form anions and primary, secondary and tertiary butyl iodides to produce butylates. Product Distributions were determined by using gcms. It was concluded that electron transfer and S//N2 reactions were in competition during reductive alkylation of aromatic compounds. Identity of the aromatic compound, alkali metal, solvent and the experimental conditions determine the mechanism that will predominate

The Elbistan lignite field

Samples have been taken systematically from a sequence of immature lignite deposited as a large reserve in Elbistan (37° 48' N 37° 51'E) 1.5-2 m.y. ago during the Pliocene-Pleistocene transition. The lignite has a high volatile content of 60-70% and a huminite reflectance of 0.27 ± 0.03. © 1988

Biomarkers of marine pollution observed in species of mullet living in two eastern Mediterranean harbours

The activities of enzymes associated with xenobiotic metabolism and/or oxidative processes, and the levels of aromatic-DNA adducts, have been determined in the livers of grey mullet (Oedalechilus labeo and Lisa ramada) living in two eastern Mediterranean harbours. Glutathione peroxidase (GSH-P) activity was 2.5 times higher (~ 9 IU g-1 liver) and glutathione reductase (GSSG-R) activity was twice as high (~ 2.5 IU g-1 liver) in fish from the more polluted harbour at Mersin than in the harbour near Erdemli. Superoxide dismutase (SOD) activity was 25% lower (4.3 IU g-1 liver) in the more polluted harbour. The concentrations of glutathione and malondialdehyde varied both with species and environment by a factor of 2.5-3. DNA adducts in liver were determined by 32P-postlabelling. In Oedalechilus labeo in the more polluted harbour, adduct levels were 258 ± 21 adducts per 108 nucleotides (mean ± SE); two groups of Lisa ramada were distinguished having 261 ± 48 and 30 ± 6 adducts per 108 nucleotides, respectively. The average adduct level in a group of mullet of mixed species in the less polluted harbour was 3.3 ± 2.3 adducts per 108 nucleotides. The results illuminate the ability of mullet to live in contaminated marine environments, and show that enzyme activities and liver DNA adduct levels can serve as indicators of marine pollution. © 1997 Taylor & Francis Ltd

Pyridine extracts of solid fuels

Pyridine extracts of a coking coal and of two lignites have been further separated and the 1H and 13C n.m.r. spectra of the various fractions have been recorded. Three methods of separation were investigated: gel-permeation chromatography, successive extraction with petroleum ether and with benzene as used by previous workers for supercritical-gas extracts, and the classical extraction of the fractions. Gel-permeation chromatography gave most promise of effective separation but the fractions obtained often contained too little material to give n.m.r. spectra. The n.m.r. spectra of the chloroform-soluble material from the pyridine extracts of the coking coal were consistent with a material consisting of polynuclear aromatic nuclei joined through simple bridge structures and possibly also through direct carbon-carbon linkages. The nuclei were substituted by branched and unbranched paraffin chains, some of which were 7 or 8 carbon atoms long. It is probable that alicyclic structures were also present. The aromatic nuclei were mobile in solution. 60% of the carbon atoms were aromatic, and it can therefore be calculated that the molecular weight per aromatic nucleus was 200-300. It is suggested that 13C n.m.r. spectra may be used to characterize chemicals likely to confer coking properties on solid fuels. © 1979.We are grateful to Dr P. Wybel of the Varian Laboratories for arrangingt he field-desorptiona nd field-ionization mass spectrometry. The work has been generouslys upported by the Turkish Scientific and Technological Research Council (TBTAK)

The potential effect of development on the sustainability of the Thai-Laos Mekong

Paper examining the potential effect of development on the sustainability of the Thai-Laos Mekong

Hydrocarbons generated by hydropyrolysis of suspended marine particulate organic matter: Relationship to the oceanography of the Black Sea and the Rhodes Gyre

The suspended particulate organic matter, SPOM, in the autumnal Black Sea has been characterised using catalytic hydropyrolysis (HyPy) of the total (bound plus free) lipid material. The technique, which generates maximum yields of volatile products from sediments, kerogens and phytoplankton, was followed using gas chromatography and gas chromatography/mass spectrometry. The generated alkanes were dominated by n-C18, hypothesised to arise predominantly from unsaturated C18 fatty acids. Steranes were generated from reductive conversion of free and bound sterols. The generation of branched alkanes and especially of hopanes provided formal evidence for the participation of bacteria in the mineralisation of the SPOM. Whereas similar distributions of n-alkanes were generated from SPOM sampled from different depths of the comparatively well-stirred Rhodes Gyre (eastern Mediterranean), mineralisation of the SPOM at each depth of the central Black Sea produced characteristic changes in the composition and concentration of the HyPy products. Depth profiles of the n-alkanes generated from SPOM in the region of the Rim Current were affected by the local hydrography. Polynuclear aromatic hydrocarbons (PAHs) of anthropogenic origin were present in the surface waters of the central Black Sea. Some methyl benzenes, thiophenes and pyrroles were also generated