Search

To assist the investigation of oxidation products of sulphur compounds in high-boiling crude oil fractions, the mass spectra of several bisanellated thiophenediones were recorded with a mass spectrometer using 70 eV electron impact. The model substances were seven bisanellated dicyclopenta[b,d]thiophenediones, the benzo- (with and without methyl substituents), naphtho- and thieno-systems being anellated. Spectra were interpreted for both neutral fragmentation and double-charged ions. All thiophenediones yield a high proportion of molecular ions, and show characteristic fragmentation, especially the loss of CO and CO + CS.

Es werden Ringschlusse mit der 3,5-Diphenyl-2,4-thiophendicarbonsaure und ihren Derivaten 2 untersucht. Mit gleichen funktionellen Gruppen in 2- und 4-Stellung am Thiophenring tritt Ringschlus zum Indeno[1,2-c]thiophen-System 3 ein. Das Indeno[2,1-b]thiophen-System 4 ist das Reaktionsprodukt aus 5-Chlorformyl-2,4-diphenyl-3-thiophencarbonsaure-methylester (2d) mit der reaktiveren funktionellen Gruppe in 5-Stellung am Thiophenring. Das Indeno[2,1-b]thiophen 4b ist das Ausgangsprodukt fur 6,11-Dihydrodiindeno[1,2-b:1′,2′-d]thiophene 5. Die mit Truxen verunreinigte Stammverbindung 5 entsteht auch aus 3,5-Diphenyl-2,4-thiophendimethanol (2f) mit Polyphosphorsaure. Sulful Compounds in Crude Oil, II. - 6,11-Dihydrodiindeno[1,2-b: 1′,2′-d]thiophenes Ring closures with 3,5-diphenyl-2,4-thiophenedicarboxylic acid and their derivates 2 have been studied. Ring closure to the indeno[1,2-c]thiophene system 3 occurs with identical functional groups in the 2- and 4-position at the thiophene ring. The indeno[2,1-b]thiophene system 4 is the reaction product from methyl 5-chloroformyl-2,4-diphenyl-3-thiophenecarboxylate with the more reactive functional group in the 5-position at the thiophene ring. The indeno[2,1-b]thio-phene 4b is the starting material for 6,11-dihydrodiindeno[1,2-b:1′,2′-d]thiophenes 5. The with truxene contaminated parent compound 5 is also obtained from 3,5-diphenyl-2,4-thiophenedimethanol (2f) with polyphosphoric acid.

Starting with methylene ketones 2,5-diphenylthiophenes and b,d-anellated thiophenes are prepared. Aus Methylenketonen werden 2,5-disubstituierte und b,d-anellierte Thiophene hergestellt.

70 eV-Mass spectra of three anellated and two non-anellated thiophenecarboxylic acids and thiophenecarboxylic acid esters, as well as three 1,2,3-thiadiazoles, are discussed with respect to their neutral losses. Compounds investigated are intermediates of the synthesis of bisanellated thiophenes, which are suggested as reference compounds for identifying sulphur heterocycles in high boiling crude oil fractions. The thiophene ring is anellated with thieno or naphtho groups, or has two carboxylic acid functional groups. An indeno system is fused in two different ways to the thiadiazole ring, producing two isomeric structures. The thiophenes 1–5 have high molecular ion percentages and show characteristic fragmentations. This is the loss of CO2 or 2CO2 (M-44, M-88) in the case of the carboxylic acids. The carboxylic acid esters lose partially (M-31) or completely (M-59) the ester group, also in conjunction with the simultaneous loss of CO (M-87). The thiadiazoles 6–8 show in contrast only small percentages of the molecular ions. The loss of N2 (M-28) also in combination with CO (M-56 for 6) and CS (M-72 for 7 and 8) is typical for this class of compounds.

Fossil fuels and products made from them vary in sulfur content according to different origins and refining operations. The following sulfur contents are known: 0.05–13.95% for crude oils1, 0.2–12% for oil shales2,16, 0.4–11.5% for tar sands3 and 0.03–1% for syncrudes from coals4.5. The low sulfur contents of syncrudes from coals originate in the hydrogenation processes by which the coals are liquefied and at the same time partially desulfurized.

Sulfur reacts with indene, indane or diindenes (3,5-7,9,10) to give dihydrodiindeno[b,d]thiophenes (4,8,11). Schwefel reagiert mit Inden, Indan oder Diindenen (3,5-7, 9, 10) zu Dihydrodiindeno[b,d]thiophenen (4,8,11).

Measured drop-size distributions are presented which were obtained by the atomization of water with hollow-cone nozzles. The drop-size distributions were determined using a scatteredlight particle size counting analyser at various locations in the droplet cone. These local distributions change systematically from the cone's axis to its border. To acquire the drop-size distribution of all the drops the local distributions have to be superimposed. The spatial mass flow distribution in the cone can be calculated from these measurements.

4,5-Anellierte 2-Aryl-6-oxo-6H-cyclopenta[b]thiophen-3-carbosaure-methylester 1 reagieren mit methanolischem Kaliumhydroxid unter Spaltung des Cylopentadienon-Ringes zu 2-Aryl-4-(carboxyaryl)-3-thiophencarbonsauren 6a – c order Estern 5. Der Mechanismus wird diskutiert. Sulfur Compounds in Crude Oil, IV. - Alkaline Cleavage of 4,5-Annulated Cyclopenta[b]-thiophen-6-ones 2-Aryl-4-(carboxyaryl)-3-thiophenecarboxylic acids 6a – c or esters 5 are formed from 4,5-annulated methyl 2-aryl-6-oxo-6H-cyclopenta[b]thiophene-3-carboxylates 1 by cleavage of the cyclopentadienone ring with methanolic potassium hydroxide. The mechanism is discussed.

Synthesen zu den Dihydrodiindeno[b,d]thiophenen 1–3 wurden untersucht. 1–3 entstehen bei der Thermolyse des 8H-Indeno[1,2-d]1,2,3-thiadiazols (10) oder 4H-Indeno[2,1-d]1,2,3-thiadiazols (13) oder durch Reduktion der zugehorigen Diketoverbindungen 17, 19 und 21, die zuganglich sind durch Thermolyse des Indeno[1,2-d]-1,2,3-thiadiazol-8-ons (16) oder aus 2,3-Dichlorinden-1-on (23) mit Na2S. Mechanismen mit analogen Intermediaten erklaren die Bildung der Indenothiophene. – Eine weitere Synthese des Diindeno[1,2-b:2′,1′-d]thiophen-10,11-dions (21) geht von der 2,5-Diphenyl-3,4-thiophendicarbonsaure (29) aus. – 10,11-Dihydrodiindeno-[1,2-b:2′,1′-d]thiophen (3) ist das bekannte Schwefelungsprodukt des Indans; die Struktur von 3 wird richtiggestellt. Sulfur Compounds in Crude Oil, III. - Dihydrodiindeno[b,d]thiophenes Syntheses to the dihydrodiindeno[b,d]thiophenes 1–3 have been studied. 1–3 were prepared by thermolysis of 8H-indeno[1,2-d]-1,2,3-thiadiazole (10) or 4H-indeno[2,1-d]-1,2,3-thiadiazole (13) or by reduction of the corresponding diketones 17, 19, and 21 which were obtained by thermolysis of indeno[1,2-d]-1,2,3-thiadiazol-8-one (16) or from 2,3-dichloroinden-1-one (23) with Na2S. Mechanisms with analogous intermediates explain the formation of the indenothiphenes. – Another synthesis of diindeno[1,2-b:2′,1′-d]thiophene-10,11-dione (21) starts from 2,5-diphenyl-3,4-thiophenedicarboxylic acid (29). – 10,11-Dihydrodiindeno[1,2-b:2′,1′-d]thiophene (3) is the known sulfurization product of hydrindene, the structure of 3 is corrected.

Due to their usefulness as model substances for the analysis of sulphur compounds in high boiling crude oil fractions six bisanellated thiophenes were investigated with a mass spectrometer using 70 eV electron impact. The model substances are fully conjugated systems or contain two methylene groups. The spectra are interpreted for both neutral fragments and double-charged ions. Under electron impact, all thiophenes yield a high proportion of molecular ions and display characteristic fragmentation.

To assist the investigation of oxidation products of sulphur compounds in crude oil, the mass spectra of sulphones and sulphoxides of two anellated thiophenes were recorded with a mass spectrometer using 70 eV electron impact. Spectra were interpreted for both neutral fragmentation and double-charged molecular ions. The molecular ions of the S-oxides are less abundant than those of the corresponding thiophenes. O-loss is characteristic for the sulphoxides and SO-loss for the sulphones.