Colloidal dispersions of Cu-2[Fe (CN)(6)] have been prepared in the nanodomain water pools of water/ AOT/n-heptane water-in-oil microemulsion at various [water]/[AOT] mole ratios, iv, by reacting CuSO4 with K-4[Fe(CN)(6)]. The UV-visible absorption spectra of the isotropic molecular aggregates of Cu-2[Fe(CN)(6)] surrounded by a layer of amphiphile AOT have been measured. The hydrodynamic diameter, diffusion coefficient, and the polydispersity index of the colloidal dispersions prepared in the absence and presence of gelatin at different omega have been determined by the dynamic light scattering method; the static light scattering method has been employed to estimate the average particle weight of the dispersion. The formation of Cu-2[Fe(CN)(6)] in the dispersion has been established by X-ray diffraction measurements. The size and shape of the colloidal dispersions and the isolated particles have been examined by the transmission electron microscopy and scanning electron microscopy methods. The enthalpies of formation of Cu-2[Fe(CN)(6)] in aqueous and in the microemulsion media have been calorimetrically determined.