Synthesis and Characterization of Supramolecular Nanotubes of Tetraphenylethylene-Porphyrin Conjugates

Abstract

A series of tetraphenylethylene-porphyrin conjugates ((TPE)nH2Ps, n = 1, 2, and 4) are synthesized by Lindsey condensation and Adler-Longo methods. (TPE)nH2Ps are structurally characterized by 1H-NMR and MALDITOF mass spectrometry, and the photophysical and electrochemical properties are analyzed by UV-Vis absorption and fluorescence spectroscopies, and cyclic voltammetry. As the number of TPE increase, the porphyrin band gaps were slightly decreased, together with a small bathochromic shift of absorption and red shift in emission bands. The theoretical DFT calculations also showed good agreement with the experimental results. From TEM observations, (TPE)2H2P and (TPE)4H2P formed nanotubes with a diameter of 10 to 20 nm and a length of about 100 nm in a chlorobenzene/n-hexane (1:1 v/v) mixture and found that the wall thickness of nanotubes increased with the number of TPE moieties.