caa a22 4500 465733077 CHVBK 20180323111746.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF02218164 doi (NATIONALLICENCE)springer-10.1007/BF02218164 On the postronium spin exchange reactions promoted by 3d aqua ions [Elektronische Daten] [A. Fantola Lazzarini, E. Lazzarini] In order to ascertain possible relationships between the rate constants, KSE, of positronium, Ps, spin exchange /SE/ reactions promoted by 3d aqua ions and the electron configuration of the ion, the KSE's of Mn aq 2+ and Co aq 2+ aqua ions were measured together with that of [Cr(NH3)6]3+. The KSE's values obtained are discussed together with those of the Cr aq 3+ , Fe aq 2+ , Ni aq 2+ and [Ni(NH3)6]2+ ions previously measured. It was found that Cr aq 3+ and Mn aq 2+ KSE's are ∼1 M−1ns−1, while those of Fe aq 2+ , Co aq 2+ and Ni aq 2+ ions are ∼2.5 M−1ns−1. Thus the KSE values of 3d aqua ions do not depend solely on the number of their unpaired electrons as it was found for the 4f aqua ions. The trend observed parallels that of the electron delocalization from the metal atom; the delocalization occurs only with Fe aq 2+ , Co aq 2+ and Ni aq 2+ ions, but not with the Cr aq 3+ and Mn aq 2+ aqua ions. The trend of the KSE's of aqua, ammine and perhaps of chloro complexes parallels that of ligand capabilities to cause d-electron cloud expansion, and thus d-electron delocalization from metal atoms. Akadémiai Kiadó, 1990 Fantola Lazzarini A. Istituto Ingegneria Nucleare, CeSNEF, Politecnico di Milano, Via Ponzio 34/3, 20133, Milan, Italy aut Lazzarini E. Istituto Ingegneria Nucleare, CeSNEF, Politecnico di Milano, Via Ponzio 34/3, 20133, Milan, Italy aut Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 144/3(1990-02-01), 203-213 0236-5731 144:3<203 1990 144 10967 https://doi.org/10.1007/BF02218164 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02218164 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fantola Lazzarini A. Istituto Ingegneria Nucleare, CeSNEF, Politecnico di Milano, Via Ponzio 34/3, 20133, Milan, Italy aut NATIONALLICENCE 700 1- Lazzarini E. Istituto Ingegneria Nucleare, CeSNEF, Politecnico di Milano, Via Ponzio 34/3, 20133, Milan, Italy aut NATIONALLICENCE 773 0- Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 144/3(1990-02-01), 203-213 0236-5731 144:3<203 1990 144 10967 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer