Synthesis of bifluorene-based molecular materials: effect of C-9 spirocyclohexane functionalization and end-group tailoring

The preparation and properties of the first spirocyclohexane-functionalized bifluorene-based monodispersed molecular materials is described. The obtained compounds were characterized by 1H NMR, 13C{1H} NMR, IR, DSC, UV–vis and photoluminescence both in solution and in the solid state. The molecules show emissions ranging from the blue to the blue-green region, and higher glass transition temperatures and spectral stability with respect to the analogous compounds containing 9,9,9′,9′-tetrahexyl-[2,2′]-bifluorene core. The materials were used as active layers in electroluminescent devices with ITO/PEDOT-PSS/SB1–4/Ca/Al and ITO/PEDOT-PSS/SB1–4/BCP/Ca/Al configurations.