Photophysics of AgCl doped with [Cl5Ir(N=methylpyrazinium)](-): II. ENDOR studies of C-13 enriched and D-2 exchanged complexes

Additional information has been obtained on the structure of donor complexe s produced by photoelectron trapping at [Cl5Ir(NMP)](-) (NMP = N-methylpyra zinium cation) centres in AgCl microcrystals. Several different [Cl5Ir(NMP) ](-) complexes were prepared by full or partial deuteration of the NMP liga nd protons, and by isotopically enriching the methyl group carbon with C-13 . The analysis of the corresponding changes in the [Cl5Ir(NMP)](2-) powder ENDOR spectra made it possible to assign SHF lines to specific proton/deute ron sites. In addition, an SHF interaction from the methyl group carbon was resolved in the C-13-enriched compounds. These observations, combined with preliminary results for the related donor [(CN)(5)Fe(NMP)](3-) and conside ration of the g matrix, support the previous contention that [Cl5Ir(NMP)](- ) is incorporated intact into AgCl dispersions during precipitation.