Mössbauer Effect in Iron (III) Acetylacetonate and Chemical Consequences of K Capture in Cobalt (III) Acetylacetonate

Publisher Website
Google Scholar
Abstract
The resonance absorption of 14.4 keV gamma rays in Fe57 (Mössbauer effect) has been observed in Fe(III) and Co(III) acetylacetonate, the former used as an absorber against a source of Co57 diffused into metallic chromium, the latter as a Co57 labeled source against an K4Fe(CN)6 (38%Fe57) absorber. The Fe(III) acetylacetonate absorber spectrum shows a single broad line (Γ½=1.83±0.09 mm sec—1) with an isomer shift of 0.50±0.09 mm sec—1. The Co(III) acetylacetonate source shows a complex spectrum which can be resolved into a single peak assigned to Fe(III) and a quadrupole split pair of lines assigned to Fe(II). These data are interpreted in terms of the chemical consequences following K capture in Co57, and suggest a twofold preference for the stabilization of the higher charge state in the Co(III) acetylacetonate matrix. No evidence for ionic charge states higher than 3+ is observed, and it is assumed that these species—if formed as a consequence of the prior nuclear event—have been reduced to the observed states in times short compared to 10—7 sec.