Photobleaching of Triphenylamine–Phthalocyanine Entails Mixed Valence-State Triggered Self-Assembled Nanospheres

Abstract

Origin of mixed valence states from π-conjugated photoresponsive systems offers self-assembled nanostructures facilitating excellent optoelectronic properties. Despite various electron-rich moieties, tethered linear π-conjugated systems generate charged ions however limited to standard redox-active materials until now, which further extended to macrocyclic systems. Herein, we report three carbazole and triphenylamine-assisted phthalocyanine derivatives (1, 2, and 3) and discussed the nature of photobleaching/photoionization by illumination with an excitation wavelength of 350 nm. Detailed UV–visible absorption and cyclic voltammetry studies revealed that three derivatives are bleached during irradiation; however, 3 exhibits mixed valence species in CHCl3 when compared to 1 and 2. Microscopic analysis suggested that ionized 3 forms nanospheres with an average diameter of 100–400 nm upon methanol vapor diffusion approach. Thus, photoresponsive mixed valence systems facilitated well-defined nanostructures, thereby advantageous in various electronic and biological applications.