Surfactant assisted self-assembly of zinc 5,10-bis (4-pyridyl)-15,20-bis (4-octadecyloxyphenyl) porphyrin into supramolecular nanoarchitectures

Abstract

The surfactant assisted self-assembly (SAS) method has been used in the formation of nanocubes, nanorods and microrods from zinc 5,10-bis (4-pyridyl)-15,20-bis (4-octadecyloxyphenyl) porphyrin. By the dropwise addition of chloroform solution of the zinc porphyrin into an aqueous solution of cetyltrimethylammonium bromide (CTAB), cuboidal nanostructures are formed at the initial stage. The nanocubes are transformed into nanorods and microrods by aging under ambient conditions. The longer nanorods with well defined edges have been formed with lower concentration of porphyrin solution whereas the shorter nanorods have been formed with higher concentration of zinc porphyrin. The synergistic effect of hydrophobic interactions by the long alkyl chains substituted on the peripheral phenyl rings of porphyrin and axial coordination of pyridyl nitrogen atoms with central zinc is mainly responsible for the formation of different nanostructures. The nanostructures were characterized by UV–visible spectra, fluorescence spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), IR spectroscopy and X-ray diffraction (XRD) pattern.