Dehydration process in recently synthesized porous inorganic salts formed by large cluster anions [Re6X8(CN)6]4- (X= S, Se), transition metal cations and water molecules has been investigated. Desolvation process of the complex Co(DMF)6[Mo6Br8(NCS)6], where DMF dimethylformamide. has been studied. CoK, MoK and ReL3 XAFS measurements of these new complicated compounds before and after annealing in vacuum at temperature up to 250 degrees C were performed. Changes of electronic and spatial structure of these compounds under the heating process have been established and adequate structural models of the amorphous compounds obtained are suggested and discussed.