Positronium formation and inhibition in binary solid solutions on Al(III) and Co(III) tris(acetylacetonates)

Evidence of the participation of electronic excited states in the mechanism of positronium formation in substitutional Tb1−xEux(dpm)3 solid solutions studied by optical and positron annihilation spectroscopies

“…6(a). These results show that this system behaves similarly to those involving the same dpm ligand and acetylacetonate-acac ligand previously studied: [13][14][15]18,38,39 Ps formation is completely inhibited as a function of guest concentration. The experimental data obey the Stern-Volmer expression satisfactorily, I o 3 /I 3 = 1 + kx, where I 3 and I o 3 stand for the o-Ps formation relative intensities of the solid solutions and Tb(dpm) 3 matrix compound, respectively, x represents the solid solution composition in terms of fraction, and k is the total inhibition constant.…”

“…[13][14][15][16][17][18][19][20][21][22][23] These studies have evidenced the importance of the chemical properties of both the ligand and the central metal ion in Ps formation. [13][14][15][16][17][18][19][20][21][22][23] In lanthanide complexes, positronium formation has been observed in all trivalent ions through the lanthanide series, except in many Eu(III) complexes. [19][20][21] Actually, positronium formation in an Eu(III) ion had not been reported until the formation of Ps in high luminescent Eu(III) complexes was observed by our group in 2006.…”

“…The Stern-Volmer equation is consistent with this competitive reactional kinetic mechanism into the spur, and has been used frequently to fit the experimental variation of the positronium formation intensity versus the concentration of an inhibitor solute in liquids 11,12 and solid solutions. [13][14][15] The positronium chemistry of solid coordination compounds has been studied sporadically since the 1980s. [13][14][15][16][17][18][19][20][21][22][23] These studies have evidenced the importance of the chemical properties of both the ligand and the central metal ion in Ps formation.…”

“…[13][14][15] The positronium chemistry of solid coordination compounds has been studied sporadically since the 1980s. [13][14][15][16][17][18][19][20][21][22][23] These studies have evidenced the importance of the chemical properties of both the ligand and the central metal ion in Ps formation. [13][14][15][16][17][18][19][20][21][22][23] In lanthanide complexes, positronium formation has been observed in all trivalent ions through the lanthanide series, except in many Eu(III) complexes.…”

“…Chem. Phys., 2012,14,[9996][9997][9998][9999][10000][10001][10002][10003][10004][10005][10006][10007] Evidence of the participation of electronic excited states in the mechanism of positronium formation in substitutional Tb 1Àx Eu x (dpm) 3 solid solutions studied by optical and positron annihilation spectroscopies F. Fulgeˆncio …”