Über die Bromierung von 9-Vinylcarbazol

Zusammenfassung Bei der Bromierung von N-Vinylcarbazol wird unter verschiedenen Reaktionsbedingungen 3.6-Dibromcarbazol, 3.6-Dibrom-9-(1.2-dibromäthyl)carbazol, 3.6-Dibrom-9-(1-methoxy-2-bromäthyl)-carbazol und 3.6-Dibrom-9-(1-äthoxy-2-bromäthyl)-carbazol erhalten. Aus 9-Äthylcarbazol wurde 3.6-Dibrom-9-äthylcarbazol, aus 1.2-Bis(9-carbazyl)cyclobutan 1.2-Bis[9-(3.6-dibromcarbazyl)]cyclobutan und aus Poly-N-vinylcarbazol Poly-3.6-dibrom-9-vinylcarbazol dargestellt. Der Bromierungsmechanismus wird diskutiert.

---

Bromination of N-vinylcarbazole

Bromination of N-vinylcarbazole under various conditions gives 3.6-dibromocarbazole, 3.6-dibromo-9-(1.2-dibromoethyl)-carbazole, 3.6-dibromo-9-(1-methoxy-2-bromoethyl)carbazole, and 3.6-dibromo-9-(1-ethoxy-2-bromoethyl)carbazole. 3.6-Dibromo-9-ethylcarbazole and 1.2-bis[9-(3.6-dibromocarbazyl)]-cyclobutane have been obtained from the corresponding carbazole derivatives, and poly-N-vinylcarbazole was brominated to poly-3.6-dibromo-9-vinylcarbazole. The bromination mechanism is discussed.

---

---

An dieser Arbeit nahm ich als UNO-Stipendiat teil, wofür ich der UNO sehr zu Dank verpflichtet bin.     

Solute absorption into molten polystyrene

The equilibrium volatilities at near infinite dilution of various solutes absorbed in molten polystyrene have been determined by a gas chromatographic technique. This method is much more rapid, although, with the present apparatus, probably less accurate than conventional static techniques. The primary parameters obtained from measurements of retention volumes are the Henry's law constants, from which are derived the weight and volume fraction activity coefficients, the Flory-Huggins interaction parameters, and the heats of dilution and solution. Of the solutes investigated, 2-butanone (MEK) was the least, and benzene the most compatible (highest and lowest volume fraction activity coefficients, respectively) with molten polystyrene. A small, but definite, variation of the activity coefficients with polystyrene molecular weight was observed.     

The role of electronic factors in reagents in controlling thestereochemistry of arylsulfenyl chlorides addition

For a series of substituted arylsulfenyl chlorides the stereochemistry of Ad_E-reactions with a series of substituted Z- and E-β-deuterostyrenes has been elucidated. Non-stereospecific reaction was observed only for the pair 2,4-dinitrobenzenesulfenyl chloride-p-methoxystyrene; for all the other reactants the reaction proceeded in a strictly stereospecific manner.     

Über Blei (II)-oxidhydrat der Zusammensetzung 3PbO·H2O

Lead oxide hydrate mentioned in the earlier literature with several formulas between PbO · H₂O and PbO · 0.33 H₂O has been synthesized and investigated by high resolution X-ray powder methods, thermogravimetry and infrared spectroscopy. The unit cell was found from 62 powder reflections to be tetragonal with a = 8.009 ± 0.003 Å, c = 9.312 ± 0.005 Å, Z = 12 [PbO · 0.33 H₂O]. These data were confirmed by WEISSENBERG and Precession photographs of single crystals grown as a corrosion product on metallic lead. The space group is D–P4/mnc or C–P4 nc. Thermogravimetric measurements, corrected for a slight content of superficially bound carbon dioxide detected by infrared spectroscopy, lead to the most probable formula 3 PbO · H₂O or PbO · 0.33 H₂O. As infrared spectra show the presence of a HOH deformation vibration, the compound is considered to be an oxide hydrate and not an oxide hydroxide of lead.     

Die Auswertung von γ-Spektren mit Programmen

Modern activation analysis requires the application of efficient data processing for the evaluation of theγ-spectra of samples containing several radionuclides, especially if preceding radiochemical separations are to be largely or completely eliminated. The essential aspects of two programs for quantitative determinations and qualitative identifications are described. These programs are based on the least squares analysis of the total spectrum and the search, arrangement and processing of the photopeaks. With respect to their details the programs are adapted for application on the computer IBM-360/75.