translate English to French: In the salts ClO2Cd(ClO4)3, NO2Cd(ClO4)3, and (NO2)2Hg(ClO4)4 the anions have polymeric arrangements; their structures are analogous to those of ACuCl3, NO2Co(ClO4)3, and (NO2)2Cu(ClO4)4, respectively.
Dans les sels ClO2Cd(ClO4)3, NO2Cd(ClO4)3 et (NO2)2Hg(ClO4)4, les anions sont des polymères; leurs structures sont analogues respectivement à celles de ACuCl3, NO2Co(ClO4)3 et (NO2)2Cu(ClO4)4.