Molecular units in ionic crystals via abstraction of matrix atoms by implanted metal ions

1991

Chemical reactions induced by recoil implantation were studied focussing on parent type species in tris(^-diketonato)metal(III) complexes. The yield of the substitution reaction *M + M(acac)3 -*M(acac)3 + M was dependent on the force constant ratio K(*M -0)/K(M -O), showing that competition occurred between *M and M in the cage of the acetylacetonate complex.In the case of *Cr implantation in Co(acac)3, an exceptionally large yield could be explained by formation of Co(acac)2, whose central metal easily exchanges with *Cr, and by pickup of acac. When different ^-diketonate complexes were examined in the reaction *Cr + M(^-dik)3•Cr(^-dik)3 + M the yield was dependent on the stability of the M(^-dik)3 complexes. A reaction model to explain these results reasonably was presented.

Section: Methodsmentioning

confidence: 55%

Parent Type Chemical Species Formed by Recoil Implantation Reaction in Tris(β-diketonato)metal(III)

1991

“…The former depends on the particle size of the source material [5], and the latter on various conditions which should be considered as controlling factors in ordinary hot atom chemistry in solids. Recent studies by RÖSSLER et al [8] showed interesting features of reaction mechanisms in recoil implantation. Considering the relative importance of replacement and abstraction reactions which were introduced in recoil implantation reaction mechanisms by them, the latter factors may be more important than the former in our system also.…”

Section: Discussionmentioning

confidence: 98%

Synthesis of Tc and Pm Benzoyltrifluoroacetone Complexes by Recoil Implantation

Saito

1982

Synthesis o/Tc^'ibta), /Synthesis o/Pm(bta) 3 /Recoil implantation j Sublimat ography of neutral complexes/Chromatographic separation Summary Hitherto unknown compounds, tris(benzoyltrifluoroacetonato) technetium (III) and tris(benzoyltrifluoroacetonato)promethium(III) were synthesized by recoil implantation. Uranium fission, (γ, ρ) or (d, xn) recoil reactions were used to prepare these complex compounds. Sublimation and other chromatographic separation techniques were applied to prove formation of these new chemical species.

“…The latter is a major constituent and the former is a minor constituent. A Tc-acac cationic species of a Tc(acac)2 type in the solid may be produced both by the process of ligand abstraction [6] and by the process of replacement of the central metal of the complex followed by partial loss of the ligands. The origin of the reduced form of technetium is considered as an interstitial atom implanted in molecular crystals of complex Compounds.…”

Section: Discussionmentioning

confidence: 99%

“…RÖSSLER et al [6] stated that ligands were abstracted by interstitial atoms and then parent-like chemical species were formed in the system of K2ReX6 type Compounds.…”

Section: Introductionmentioning

confidence: 99%

Studies on Chemical Behavior of Technetium Atoms Implanted in Metal Acetylacetonates

1983

Recoil implantation /Chromatographie Separation ofTcjOxidation of implanted atoms/Time-dependent isotope effect /Metal acetylacetonate eatehers SummaiyWater soluble chemical species of technetium which were obtained in deuteron bombarded mixture of molybdenum and metal acetylacetonate complexes were studied by cation exchange chromatography and by gel chromatography. The result on cation exchange chromatography, just after Irradiation, indicates that 99mTc implanted directly by the 98Mo(d, n)99mTc reaction shows the same distribution of chemical forms as 95TC implanted simultaneously. However a remarkable difference of the distribution between 99mTc and ^Sjc was observed by Standing after irradiation. This "time-dependent isotope effect" was ascribed to the fact that 99mTc produced by the 99MO decay after implantation has a strong tendency to become a chemical entity which is more easily oxidized to pertechnetate than 9STC. Moreover, oxidation to pertechnetate was inhibited in the absence of oxygen. This Observation suggests that the charged center produced by the (3"-decay of the interstitial atom plays an important role in the oxidation process. An electrostatic interaction between the positively charged interstitial and negatively charged oxygen is a possible explanation for the process.