Surfactant charge mediated shape control of nano- or microscaled coordination polymers: The case of tetrapyridylporphine based metal complex

In this work, CuTPyP (TPyP = 5,10,15,20-tetrapyridylporphine) single crystalline 2D nanoplates and 3D polyhedra of nano-octahedrons and microspindles can be selectively obtained by changing the type as well as the concentration of the surfactant via a simple surfactant-assisted chemical solution method at room temperature. Under anionic surfactant of sodium dodecyl sulfate (SDS), high purity uniform nanoplates were obtained, while under cationic surfactant of cetyltrimethylammonium bromide or tetrabutylammonium bromide, monodispersed microspindles and nano-octahedrons were obtained. The as synthesized products are characterized by UV-vis spectroscopy, fluorescence emission spectroscopy, X-ray diffraction pattern, scanning electron microscopy, and transmission electron microscopy. The crystal growth mechanism in the presence of either positively charged or negatively charged surfactant was studied by changing the preparation parameters. The rational shaping mechanism for different surfactants was thus promoted. This work provides a simple and mild approach to obtain high-quality 2D MTPyP nanocrystals through an anionic surfactant controlled synthesis process. It should be transferable to the shape control of nano- or microscaled metal-organic materials with related growth mechanisms.