EPR studies of radiation damage in metal acetates: The hydrated lead (II) salt

Abstract

An EPR study of x-irradiated lead acetate trihydrate at 77 °K has strengthened the identification of two recently reported species, Pb1+ and PbH2+. The first of these results from radiation-induced electron trapping by coordinated Pb2+ ions, and the second center consists of a hydrogen atom that is weakly associated with a plumbous ion in the crystal lattice. The radical PbCH32+ was also observed. A detailed study of the Pb1+ center reveals that the diagonal components of the 207Pb hyperfine coupling tensor are very large and anisotropic, and that the characteristic g tensor is almost isotropic. These data are interpreted in terms of a bonding scheme that locates the unpaired electron in a hybridized molecular orbital that possesses 6s, 6p, and possibly some 5d, character. A comparison of our data for Pb1+ with published data for Pb3+ reveals striking differences.

An ELDOR study of methyl radical production at 77 K in irradiated acetate powders as a function of metal cation

“…For instance, in irradiated anhydrous lead(II) acetate15 crystals, Pb2+ was shown to trap holes to form Pb3+ centers while in irradiated crystals of lead acetate trihydrate, Pb2+ acted as an efficient secondary-electron trapping site to form Pb+ centers and also acted as an excellent methyl radical scavenger. 16 Somewhat similar results were also found for Hg(II) and Cd(II) in irradiated acetates.27•28…”