261 4
Wasgestian, Bailardini, Varani, Moggi, and Balzani
Quenching of the Tris(ethylenediamine)chromium(I I I ) Phosphorescence
by Some Transition Metal ions in Aqueous Solutions H. F. Wasgestian," R. Ballardini,'b G . Varani,lb L. Moggi*'C and V. Balzani'c institut fur ohysikalische Chemie der Universitat. Frankfurt a. M.,Germany: istituto Chimico deli'llniversiti, Centro di Studio suila Fotochimicz e Reetfi'~1fadegir Sfz!: Ecc!:afi dei Composrr di Coordwazione del C N . R , Ferrara ltaiy: and lstituto Chlmico
"G.Ciamician" deii'Unwersit8. Bologna, lfaly
(Received June 8. 1973)
The intensity and lifetime quenchings of the C r ( e n ) s 3 ~phosphorescence have been investigated in aqueous solution a t room temperature. It has been found that Mn,,2+. whose lowest excited state is a t 18.9 kK, does not exhibit any quenching effect, whereas Feaq2+ and Coaq2+, which have very low lying excited states (
