Synthesis and Investigation of a Symmetrical Bis(methoxycarbonyl)-Substituted Rubrene Derivative

A symmetrical rubrene derivative, 5,6-bis(4-(methoxycarbonyl)phenyl)-11,12-diphenyltetracene, was synthesized via the thermal dimerization of 1,1-diphenyl-3-[4-(methoxycarbonyl)phenyl]-3-chloroallene. The reaction proceeded with low selectivity, affording the target tetracene and the bis(alkylidene)cyclobutene by-product in nearly equal yields 25% each. The optical characteristics of this rubrene derivative were investigated, revealing bright orange fluorescence in a CHCl3 solution (λem=565 nm, ΦF=0.81, τ=11.41 ns), which is strongly quenched in the solid state (ΦF=0.01) due to aggregation.