Positronium interactions in aqueous solutions

Horstman, H.

doi:10.1016/0022-1902(65)80082-3

Cited by 14 publications

(6 citation statements)

References 16 publications

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“…The activation energies found were between 0.05 and 0. annihilation of Ps occurs, gave h,=0.65 ns-1 [27,291 . o N (29) Though I , exhibits the temperature dependence shown in Table 1, the 0-Ps yield calculated in this way remains constant over the entire temperature range investigated ( Table 2).…”

Section: Positronium Chemistry In Aqueous Solutionsmentioning

confidence: 69%

Chemistry of the Positron and of Positronium

Ache

1972

Angew. Chem. Int. Ed. Engl.

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In this progress report, the properties and behavior of the positron (“positive electron”, anti‐electron) and of the positronium, a “hydrogen atom” containing a positron instead of a proton, are considered from the chemist's viewpoint. Examples are given to demonstrate the development of positronium chemistry, in aqueous solution and in the gaseous, liquid, and solid phases, with its problems and possibilities.

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Section: Positronium Chemistry In Aqueous Solutionsmentioning

confidence: 69%

Chemistry of the Positron and of Positronium

Ache

1972

Angew. Chem. Int. Ed. Engl.

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“…Later their studies were further extended5,6 and the temperature dependence of h and r2 for positrons in certain solutions was explained. 6 Another similar problem has been studied by Goldanskii, et al., 7 and tunneling of the electron through the potential barrier from positronium to the acceptor was suggested to explain certain anomalous phenomena in positronium annihilation. Recently, this problem was attacked again by Bertolaccini, et als Extensive reviews can also be found elsewrhere.2b However, the questions raised by Trumpy3 were still not fully answered in the works mentioned.…”

mentioning

confidence: 75%

Positronium interactions in aqueous oxyacids and hydrogen compounds

Tao¹,

Green²

1969

J. Phys. Chem.

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it is small. If Ear = 0, then D(HaB-BH3) = 38.5 kcal and will be reduced by 2Ear if E,,r # 0. It is reasonable to assume 0 5 Ear 5 2 kcal and thus 34 5 D(HaBBHa) 5 38 kcal. To place this determination in perspective, Figure 11 shows the values of b, expected for critical energies corresponding to D(HaB-BH3) values of 28.4, 35.0, and 59.0 kcal. Our data for the homogeneous reaction are also shown. Additional support for our value of the diborane bond energy is obtained by noting that the magnitude of the inverse isotope effect expected for the homogeneous reaction depends on the critical energy. Figure 12 shows this dependence, and we have indicated the expected isotope effects corresponding to values of D(H3B-BH3) of 28.4, 35.0, and 59.0 kcal. Although the measured isotope effect suffers from considerable scatter, it appears good enough to exclude the high value for D(HaBBHa).If one accepts the hypothesis concerning the surface reaction, a value for D(H3B-BH3) can also be calculated from these data. The activation energy for this reaction is a "high-pressure" value and is slightly lower than the true value due to the weak surface interaction. Once again making the approximation that the reverse reaction has negligible activation energy, a value of D(HaB-BH3) of 36 kcal/mol is obtained.Besides the assumption concerning Ear above there are a number of other sources of error which we have estimated as follows. By comparison with the CHaNC the estimated error in the calculation of the absolute rate is about a factor of 2 in the rate or 1 kcal in EBf. The measurement of the area of the reactor exit orifice is probably good to 20% or 0.5 kcal in Eaf. The uncertainty in temperature gives an error of 0.6 kcal in E, ' and the random error in the measurement of b, yields an error of 0.4 kcal in E,'. We conclude that D(H3B-BHa) is 36 f 3 kcal.The lifetimes of positrons in the oxyacid-water systems, H3P04, HzSO4, HC104, "08, and water, and in the hydrogen compound-water systems, HCl, HF, "3, HzO2, and water, were determined. The short lifetime component ( T I ) , the long lifetime component ( 7 2 ) , and the intensity (12) of the long lifetime component were derived from the composite lifetime data. The connection between changes in 12, the solution composition, and hot radical reactions is discussed. Data are discussed in terms of a proposed oxidation of positronium (Ps) by H+ and of possible chemical reactions leading to compounds of Ps and some estimates of bond energies are made: PsO (2.2 The unknown bond strength of 041 in Clod-is estimated as 3.3 f 0.5 eV. 0.5 eV), PsOH ( <1.5 eV) , PsF (2.9 f 0.5 eV) , and PsCl(2.0 i 0.5 eV).

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“…Since we are dealing with a closed-shell electronic system, each occupied electronic orbital occurs twice, being associated once with spin function a and once with ß. We make the usual assumptions of orthonormality ( \ ) = 1; ( \ }) = ;, Using the fact that the electronic part of consists of n doubly occupied orbitals, this can be written in terms of summations over those molecular orbitals (5) i…”

Section: Hartree-fock Theorymentioning

confidence: 99%

“…Earlier calculations indicated positron affinities of the order of 2 eV for Cland alkali atoms. [3][4][5][6][7][8][9] This paper is concerned with the existence of e+ complexes with relatively large organic compounds. For large compounds, containing many electrons, a variational treatment similar to that11 for e+H~is presently intractable,…”

Section: Introductionmentioning

confidence: 99%