Abstract
Adsorption and intercalation of +1 charged cationic dihydroxo (tetraphenylporphyrinato)antimony(V) bromide (1a) into an artificially synthesized smectite clay (Sumecton SA; SSA) were studied. The red shift of Soret band of 1a was observed in an aqueous clay suspension owing to the adsorption onto the clay. Analyses of X-ray diffraction of 1a-SSA complex indicate the layer structure of SSA should be kept irrespective of the addition of 1a. The expanded interlayer distance of 1a-SSA complex was determined to be 1.09 nm. This value is almost consistent with two times thickness of 1a for axial direction (0.42 nm). These results strongly suggest that 1a should be intercalated into SSA interlayer, and that the orientation of the porphyrin plane should be almost parallel to the SSA clay layer. On the other hand, both 1b- and 1c-SSA complex can not take the layer structure but the amorphous. The above results show the importance of the axial ligand structure as how to control the intercalation of porphyrins
