The vibrational spectra of normal and 2H-enriched carbonate perhydrates M2[CO3]·nH2O2(Na,n= 1.5; K, Rb, or Cs, n= 3; NH4n= 1) and those of the normal and 13C-enriched peroxodicarbonates M2[C2O6](M = Na, K, Rb, or Cs), normal and 13C-enriched Li2[CO4]·H2O, and the salts M[MCO4]·nH2O (Na, n= 1; K, or Rb, n= 0) have been recorded. Structures are proposed for these species. E.s.r. measurements indicate that some of these materials contain free radicals, the nature of which have been investigated.