Vom Rohöl zu Energie‐ und Chemierohstoffen. Erdölverarbeitung in der Mineralölraffinerie

Crude oil still is one of the most important sources of primary energy. With an annual consumption of nearly four billion metric tons it is also the most important raw material for the chemical industry. The complex process network of a modern oil refinery is used to upgrade crude oil into a wide variety of intermediates and products.     

Untersuchungen über die Löslichkeit von Molybdatophosphaten. I. Löslichkeit von Chinoliniummolybdatophosphat

Studies on the Solubility of Molybdatophosphates. I. Solubility of Quinolinium Molybdatophosphate The solubility of quinolinium molybdatophosphate was determined radiochemically under conditions of the gravimetric determination of phosphate in hydrochloric acid as well as in nitric acid media. The residue concentration of phosphate variies in the range of 10^?8 to 10^?9 mol/I. The dependence of the solubility on the reagent concentration and on the concentration of solution components was investigated and discussed variing the pore width of the filters used for separating the precipitate. The accuracy and the precision of the determination of phosphate was not influenced in practice by the solubility.     

Organic Stereochemistry. Part 6

Following the previous Part on the mechanisms of chiral recognition in pharmacology, the road was open to cover one aspect of stereoselectivity that had been evoked in Part 5 but not discussed explicitly, namely the pharmacological significance of the conformational behavior of active molecules. There, we saw how ligands and binding sites adapt to each other, but these results were not related explicitly to the conformational behavior of the ligand. The focus of the present Part is to use a few well‐known drugs, examine their conformational behavior, compare the 3D geometry of probable conformers with rigid analogs acting at the same receptor, and reflect on the concept of ‘active conformation’.     

Hochauflösende Festkörper-NMR-Untersuchungen an Kieselsäuren. III Hochauflösende 29 Si-Festkörper-NMR-Untersuchungen an synthetischen siliciumreichen Kieselsäurehydraten

Solid-State High-Resolution N.M.R. Studies of Silicic Acids. III. Solid-State High-Resolution ²⁹Si-N.M.R. Studies of Synthetic Highly Siliceous Silicic Acid Hydrates Solid-state high-resolution ²⁹Si-N.M.R. experiments were used to study the structure of the silicate layers in three synthetic highly siliceous silicic acid hydrates obtained by cation exchange reactions from the synthetic sodium silicate hydrates ilerite, magadiite and kenyaite. For each of the studied samples two well-separated N.M.R. signals have been recorded which could be assigned to Q³ - (O?Si(OSi?)₃–) and Q⁴-(?Si(OSi?)₄–) units of the silicate layers of the corresponding silicic acid hydrate. On the basis of these results the same model was used to describe the structure of the silicate layers in the studied compounds which has been already used for the interpretation of the N.M.R. results in case of the synthetic sodium silicate hydrates. Compared with the sodium silicate hydrates in the studied silicic acid hydrates a somewhat large Q⁴/Q³-ratio and a high-field shifted Q³signal have been detected. These observations were attributed to structural changes which appeared as a result of the cation exchange reactions.     

12. Österreichische Chemietage

Joint Meeting of the Slovenian & Austrian Chemical Societies, September 10 – 13, 2007, Alpen‐Adria‐Universität Klagenfurt     

Über basische Aluminiumsalze und ihre Lösungen. XVI. Kinetische Untersuchungen an niederbasischen Aluminiumchloridlösungen

Basic Aluminum Salts and their Solutions. XVI. Kinetic Studies on Low Basic Aluminum Chloride Solutions Basic aluminum chloride solutions of low basicity were prepared by different methods and investigated by means of the ferrone kinetics. In solutions prepared by expulsion of hydrogen chloride or addition of solid sodium carbonate preferably dimeric cations are formed. In solutions prepared by addition of sodium hydroxide solution or sodium carbonate solution only at very low basicity small quantities of dimeric ions are formed, at increasing basicity tridecameric ions arise. An explanation of this behaviour is given, involving the action of hydroxide ions and a possible formation of the dihydroxy-aluminum complex. The rate constant for the reaction of the dimeric ions with the ferrone reagent was determined to be k = 0.97 ± 0.06 min^?1.     

Subvalenz bei elektropositiven s‐Block‐Metallen. Unmögliches möglich gemacht

The preparation of subvalent electropositive metal compounds succeeds in general by means of three different concepts: i) Stabilization can be achieved by delocalization of electrons in metallic matrices. A formal subvalence results from the total formula, whereas on closer examination of the bonding situation an expected “normal” valence of the metal atoms according to the octet rule can be concluded. ii) According the rules of determination of the oxidation state a formal subvalence arises from the formation of homonuclear element‐element bonds or metal clusters. However, in the case of M₂²⁺ units a normal valence is realized (which is well‐known in the chemistry of mercury as Hg₂²⁺, e.g. calomel Hg₂Cl₂). iii) The stabilization of subvalent metals with the aid of expanded π*‐systems of aren ligands succeeds when the energy lies between the two first ionization energies of the alkaline earth metal.     

Über Metallocenborane. II. Mössbauer-Untersuchungen an Ferrocenylboranen

On Metallocen Boranes. Mössbauer Studies on Ferrocenylboranes Mössbauer studies on ferrocenyl-dihalogen-boranes show a decrease in the quadrupol splitting ΔE^Q with increasing Lewis acidity of the dihalogenboryl group, while the isomer shift δ_IS remains constant.