Richtlinien für die Präsentation der Methoden bei der Publikation von Rechenergebnissen – Teil A: Ab‐initio‐Berechnung der elektronischen Struktur von Molekülen

Die Übersetzung basiert auf den „Guidelines for Presentation of Methodological Choices in the Publication of Computational Results. B. Semiempirical Electronic Structure Calculations“ des Subcommittee on Theoretical Chemistry der Commission on Molecular Structure and Spectroscopy der Physical Chemistry Division der International Union of Pure and Applied Chemistry, veröffentlicht in Pure Appl. Chem. 2000 , 72, 1149–1452. Das Original wurde von James J. P. Stewart (Stewart Computational Chemistry, Colorado Springs, USA) für die Veröffentlichung vorbereitet.     

Die Wiederentdeckung der Wöhlk‐Probe

Woehlk's test is a detection reaction for lactose and maltose from 1904. It was first used clinically for the analysis of sugars in urine. In science education the test can show in a simple way the lactose content of dairy products. This is interesting because many people react intolerant to lactose. The exact reaction mechanism of Woehlk reaction (similarly: Umikoff reaction, Woehlk‐Malfatti‐proof, Fearon's test) is still unknown despite many efforts.     

Über den Technologiewandel in der Propylenoxid‐Herstellung

Propylene oxide (PO) is one of the most important intermediates for the chemical industry. It is used for the manufacture of materials such as insulating foams, solvents, deicing fluids among others and has, thus, become essential for our modern life. The first industrial production route for PO and today still the most important one is the so called chlorhydrine process. With the renouncement of chlorine, the SM‐PO and MTBE‐PO processes provide more environmentally friendly routes for the production of PO. However, Styrene and MTBE are obtained as secondary coproducts. The economic feasibility of these processes is determined not only by PO. It is also influenced by the demand of the coproducts. The CU‐PO process has been developed as a coproduct‐free variant of the SM‐PO process. The development of the highly selective catalyst titansilicalit‐1 (TS‐1) together with the vast expansion of the availability of hydrogen peroxide paved the way for the industrial realization of the coproduct‐free HPPO technology at various sites worldwide. Excellent yields and selectivities and water as an environmentally friendly byproduct characterize this new process for the production of PO. The application of homogeneous catalysts or the direct synthesis using air/oxygen and propylene are only of academic importance so far.