STM and XRD studies of the adsorption and assembling structures of phthalocyanine and porphyrin

Abstract Using scanning tunnelling microscopy (STM) and x‐ray diffraction (XRD), the assembling behaviour of substituted phthalocyanine and porphyrin on both hydrophobic and hydrophilic surfaces was investigated. Copper (II) 2,3,9,10,16,17,23,24‐octakis(octyloxy)‐29 H ,31 H ‐phthalocyanine (denoted as CuPcOC8) and 21,23‐dihydro‐5,10,15,20‐tetrakis[4‐(tetradecyloxy)phenyl]porphyrin (TTPP) molecules adsorb stably on a highly oriented pyrolytic graphite (HOPG) surface, yielding high‐resolution STM images. The results illustrate that alkyl molecular anchors can be used as a generalized approach for immobilization of organic molecules on hydrophobic surfaces. The XRD results show that on a hydrophilic substrate CuPcOC8 and TTPP form completely different assembled structures from those on a HOPG surface, which indicates that the polarity of the substrate has substantial effects on the assembling behaviour of organic molecules. Copyright © 2002 John Wiley & Sons, Ltd.