Über die Ablenkung des Lichtes im Schwarzschild-Raum

On the Deflection of Light in Schwarzschild-Space A trigonometric approximation formula for the paths of light in Schwarzschild-Space is derived. A formula for the deflection angle at the Earth is given. Then we describe and calculate an experiment, where angles change the value by 1/2 · 1.75′ without a solar eclipse being necessary.     

Steric Interactions in Organic Chemistry: Spatial Requirements of Substituents

From the very extensive factual material available on steric interactions in organic chemistry, the present paper reviews the investigations that provide information about the “size” (“spatial requirement”) of the substituents. After an introductory section on the results obtained with the aid of spectroscopic data and by analysis of chemical reactions, attention is turned to conformational processes, including hindered rotation in ethanes, in the biphenyl system, in butadienes, multiply substituted arenes, molecular propellers, and triptycenes. The main emphasis is placed on the explanation of sterically hindered ring inversions in bridged arenes, a class of compounds particularly suitable for the study of steric interactions. The results obtained by variation of the parameters in this system are also discussed with respect to the spatial requirements of organic substituents.     

Chemical Reactions in Electrical Discharges: Preparation of perfluorinated acetylenes and nitriles. Preliminary communication

Several fluorinated acetylenes and nitriles have been isolated from the reaction mixture obtained from Tesla excited fluorinated aromatic compounds. Differences in product distributions using Tesla or radio frequency discharges are discussed.     

Vitispiranes,Important Constitutents of Vanilla Aroma

The preparation of the vitispiranes 9 and 10 , identified among the volatiles of vanilla, from the theaspiranes 1 and 2 via the intermediates 4 and 5 and the allyl alcohols 7 and 8 , respectively, is described. The theaspiranes 1 and 2 can be obtained from the compounds 11–15 or 24–26 .     

Zeitliches Abklingen des Szintillationslichts von Anthrazen- undp-Terphenyleinkristallen bei Beschuß mit α-Teilchen als Funktion der Einschußrichtung

Single crystals of anthracene andp-terphenyl have been bombarded with α-particles. The angle of incidence with respect to the crystal axes was varied. The directional intensity of the scintillation light was investigated as function of the decay time of the scintillator. During the first 100 nsec after the excitation of the crystal the anisotropy of the scintillation light yield decreases starting with a value larger than that measured with pulses of 1000 nsec length. For the next 900 nsec the anisotropy remains nearly constant being still higher than 1. Therefore the anisotropy of the fast component of the scintillation light is larger than the anisotropy of the slow component. The results are discussed with reference toBirk's formula.