Strahleninduzierte freie Radikale in phosphororganischen Verbindungen

Chlorine containing phosphonic acid esters (tridilorphon-type) have been investigated quantitatively by ESR after X-irradiation at room temperature. Radical yields are between 0.2 and 1.7 radicals per 100 eV. In the case of trichlorphon the radical concentration is 7.5·1018 spins per gram at 40 Mrad.

Stabilisation and kinetics of radiation-induced radicals in the solid state matrix at high irradiation doses in dependence of storage time, oxygen-effect and temperature are discussed. The obtained results suggest a model for the behaviour of the matrix at high irradiation doses. According to this model the lattice of molecular crystals is modified by the accumulation of recombination products arising from the induced radicals. These lattice imperfections cause a diminution of stabilizing properties for the radicals. The decrease of the dose-yield-curve at higher doses than 40 Mrad and the dose-dependent radical kinetics during storage can be explained by this model.

I. Die Inaktivierung von Escherichia coli K-12 durch den Phosphonsäureester Trichlorphon

Trichlorphone is bacteriocidal for Escherichia coli K-12. The bacterial inactivation depends on the concentration and the reaction time of trichlorphone and on the growth phase of the bacteria. DDVP formed by hydrolysis of trichlorphone had a higher bacteriocidal effect than trichlorphone itself; pH-changes may modify the effectiveness. The processes that take place in the bacterial cultures containing trichlorphone are discussed.

[The history of toxicology of the "Haber's Constant"]

The "Haber's Constant", the product of concentration (in ppm) and time (in minutes) to cause death, was mainly used in connection with the development of chemical warfare agents during World War I. But up to now the Haber's Constant is important to compare toxic gases tested on many different species of animals in research and development as well as in hygiene practice. The very first experiments in this field were done long before Haber's work in 1900 by Ernest Warren (London).

Strahleninduzierte freie Radikale in phosphoroorganischen Verbindungen II

The structure of radicals in X-irradiated polycrystalline phosphonic acid esters (trichlorphontype) and trichlorphon single crystals has been investigated by ESR. At room temperature in trichlorphon the radical (R0)2 > P(O) - CHOH - ĊCl2 (R = CH3) is formed by removal of a chlorine atom. The g-factor is 2,010 and the hyperfine parameters are αH β= 7 ± 0,5 G for the isotropic β-proton and αCL= 7 - 14 G for the two anisotropic chlorine atoms.

The structure of this radical type is not influenced by a substitution of the methyl groups by larger alkyl groups (R = C2H5, C3H7, C4H9 etc.). ESR-spectra of some other irradiated insecticides are described.

Difficulties in the analysis of ESR spectra of aliphatic radicals with chlorine-hyperfine structure (especially quadrupole-effects) are discussed.