φ-Conjugated molecules based on truxene cores and pyrene substitution:Synthesis and properties

Two starburst molecules based on pyrene with truxene cores, PYT and PYET, have been designed and synthesised by Pd(0)-catalysed Suzuki coupling and Sonogashira coupling reactions, respectively. Due to the different conjugation length, the solution absorption and emission spectra of PYET in dilute THF were redshifted compared with those of PYT. The solid absorption and emission spectra of PYET were also redshifted. Their thermal decomposition temperatures (T _d) were over 400 °C, and the glass transition temperatures (T_g) were 96 and 124 °C, respectively, which showed that both materials possess good thermal stability. Electrochemical analysis implied that the HOMOs of PYET and PYT were similar.