Molecular modeling of the intercalation of porphyrins into alpha-zirconium phosphate

In this work, n-alkylamines (number of carbon atoms ranging from 3 to 10) were investigated in detail by molecular modeling as spacers for intercalating porphyrins into alpha-zirconium phosphate (alpha-ZrP). Pre-intercalated n-alkylamines can form either a flat monolayer or a canted bilayer in the gallery of alpha-ZrP. Based on the interlayer state and intercalative potential of the two modes in alpha-ZrP, it is suggested that the flat monolayer is a better spacer than the bilayer and that n-propylamine (PA) and n-butylamine (BA) in mobile monolayers are the best spacers among the n-alkylamines studied, as is also found experimentally. The intercalation behavior of TMPyP [5,10,15,20-tetrakis (1-methylpyridinium-4-yl) porphyrin] and several other porphyrins was investigated by calculating the intercalative potential. The calculated results showed that the porphyrins were densely packed in a canted monolayer model, and an increase of polarity of the substituent would facilitate the intercalation of the porphyrins.