Synthesis of asymmetric dendrimers with controllable chromophore concentration and improved electro-optical performance

Abstract

In this work, we firstly provided a simple work-up procedure to prepare a new kind of electro-optical dendrimer with an asymmetric configuration via a Cu-(I) catalyzed Huisgen-reaction. The resulting NLO dendrimers exhibited both good thermal stability and good film-forming ability. In order to investigate the influence of the asymmetric configuration on the electro-optic (EO) activities, UV-vis spectra, density functional theory (DFT) calculations and EO performance were studied. Due to their asymmetric spherical structure, two dendrimers showed weak dipole–dipole aggregation compared with traditional dendritic electro-optical materials (DESD), but they achieved better alignment after each poling process was carried out. As expected, HJ-2 exhibited 41 pm V⁻¹ in an EO coefficient test, which was higher than DESD and the guest–host polymeric system (C2 + PMMA) using the same chromophores.