Electronic Constitution of Paramagnetic 3d Complexes and Positronium Conversion Rate Constants

Abstract

Ortho-positronium may be converted into para-positronium (and vice versa) by interacting with paramagnetic compounds such as solvated electron 3d and 4f complexes, etc. The rate constants of orthointo para-Ps conversion reactions, kSE, depend on the particular paramagnetic compound considered, e.g. the kSE's of ammoniated electron (e-am), 3d and 4f aquoions are in the ratio 10:1:0.01 [1, 2]. This finding suggested that the kSE 's may depend on the spin density of unpaired electrons at the collision site between Ps and paramagnetic compound. In order to support the hypothesis, a systematic investigation was carried out, in particular, the kSE of the aquoion Cr(III) complexes listed in Table I and III were checked or measured for the first time.