Photo-driven nanotubular growth from semiconducting porphyrin-quinoxaline

Herein, we report the light triggered porphyrin linked quinoxaline (TPP-DPQ) undergoes morphological transformation from self-assembled nanobowls to nanotubes via tadpole intermediates. UV-visible absorption spectra revealed that TPP-DPQ showed near IR absorption whilst illumination suggest the formation of [H2TPP DPQ](2+)2Cl(-) in CHCl3 exclusively. Microscopic analysis of TPP-DPQ and [H2TPP-DPQ](2+)2Cl(-) depict the nanobowls and tubular morphology together with tadpole shape intermediates with an average diameter of 0.8-1.2 mu m and 0.2-0.7 mu m. Powder x-ray diffraction spectra suggest the distinct nature of crystalline phases via H-/J-aggregates. Conducting-atomic force microscopy (C-AFM) revealed nanotubes exhibits 2-fold increment when compared to nanobowls. Thus, photoinduced growth of nanostructures from porphyrin based systems promote the design of novel smart/intelligent pi-conjugated macrocyclic systems for biomimetic signaling, data processing, storage, transmission and energy related devices.