Investigation of the Deuterohaloform Synthesis.^1a A New Preparation of Chloroform-d

Abstract

Wave length in microns. Fig. 2.-Infrared spectrum of product: curve A, liquid, 0.025 mm. cell; curve B, gas, sat. vapor, 10 cm. cell; curve C, gas, 60 mm. pressure, 10 cm. cell. and 3030 cm.-1 correspond to those reported for ordinary chloroform.6•6 Several very weak minima occurring at 991, 1097 and 1171 cm.-1 possibly result from combinations of the fundamentals.Since the minimum at 1218 cm.-1 appeared to persist even in low concentrations of ordinary chloroform, it was decided to use this minimum as a basis for the quantitative analysis of the product. The standard solutions of chloroform in benzene possessed a minimum at this point and obeyed the Beer-Lambert law, as observed in Fig. 3. Transmission of the product (dotted line) corresponded to 6.1 g. of ordinary chloroform in 100 ml. of product or to a 0.960 mole fraction of chloroform-d. The average deviation as estimated from the results of three determinations was 0.008 mole fraction units.Assuming equimolar volumes, the observed density increment of the product as compared to the calculated corresponds to a 0.952 mole fraction, in good agreement with the above analysis.

The Effects of Spatially Heterogeneous Prey Distributions on Detection Patterns in Foraging Seabirds

“…As an example, in the ocean, high productivity areas are separated by larger areas of lower productivity [10,54]. A simple analytical calculation can show that a forager crossing an heterogeneous medium composed of patches of equal and small sizes, although with power-law distributed prey densities, has an exponential p(L) [68]. Hence, not only prey density distributions but the spatial arrangement of prey density fluctuations seem to be a crucial element to obtain non-exponentially distributed detections.…”

Reactions of biological antioxidants: I. Fe(III)‐catalyzed reactions of lipid hydroperoxides with α‐tocopherol

“…The intermediate with ~kma x 255 nm is not known, but a-tocopherol quinone methine (16) is a major suspect. Under the conditions of the reactions, 8a-ethoxy-atocopherone (17), which has an absorption maximum at 241 nm in ethanol (18), may possible form; however, the spectral data for tocopherone and other products of a-tocopherol oxidation show ~kma x values well removed from 255 nm.…”

“…t~-Tocopherol can undergo oxidation to form a variety of products (17)(18)(19), including a-tocopherol quinone (20). Free-radical oxidation can yield ot-tocopherol quinone methine (16).…”