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

Abstract

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