Morphology Controlled Nanostructures Self‐Assembled from Phthalocyanine Derivatives Bearing Alkylthio Moieties: Effect of Sulfur–Sulfur and Metal–Ligand Coordination on Intermolecular Stacking

To investigate the effect of sulfur–sulfur and metal–ligand coordination on the molecular structure and morphology of self‐assembled nanostructures, metal‐free 2,3,9,10,16,17,23,24‐octakis(isopropylthio)phthalocyanine H 2 Pc(β‐SC 3 H 7 ) 8 ( 1 ) and its copper and lead congeners CuPc(β‐SC 3 H 7 ) 8 ( 2 ) and PbPc(β‐SC 3 H 7 ) 8 ( 3 ) are synthesized and fabricated into organic nanostructures by a phase‐transfer method. The self‐assembly properties are investigated by electronic absorption and Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). Experimental results reveal different molecular packing modes in these aggregates, which in turn result in self‐assembled nanostructures with different morphologies ranging from nanobelts for 1 through nanoribbons for 2 to cluster nanoflowers for 3 . Intermolecular π–π and sulfur–sulfur interactions between metal‐free phthalocyanine 1 lead to the formation of nanobelts. The additional CuS coordination bond between the central copper ion of 2 and the sulfur atom of the adjacent molecule of 2 in cooperation with the intermolecular π–π stacking interaction increases the intermolecular interaction, and results in the formation of long nanoribbons for 2 . In contrast to compounds 1 and 2 , the special molecular structure of complex 3 , together with the intermolecular π–π stacking interaction and additional PbS coordination bond, induces the formation of Pb‐connected pseudo‐double‐deckers during the self‐assembly process, which in turn further self‐assemble into cluster nanoflowers. In addition, good semiconducting properties of the nanostructures fabricated from phthalocyanine derivatives 1 – 3 were also revealed by I – V measurements.