Synthesis and characterization of pyrimidine-containing hexaarylbenzene derivatives†
Abstract
Three pyrimidine-containing claw-shaped unusual hexaarylbenzene derivatives have been successfully synthesized by cobalt-catalyzed cyclotrimerization of corresponding 3,3′-diaryldiphenylacetylenes. Cyclotrimerization of symmetric tolan derivative 6 gave symmetric product 1, while unsymmetric tolan derivative 15 afforded two geometric isomers, C3-symmetric 2 and unsymmetric analogue 3, which have been successfully separated by preparative thin-layer chromatography in 1 : 2 ratios. The coordination of 1 with Ag+, Cu2+ and Zn2+ was studied by UV-vis, fluorescence spectra and TEM.