New Copper Complex Derivatives Including Bis-Dipyrrinato Ligand for Color Filter Pigments

Abstract

Four red compounds for color filter (CF) pigments in which phenyl, 4-chloro-phenyl, 4-fluoro-phenyl and pentafluorophenyl groups are substituted to 5-position of dipyrrinato group based on bis-dipyrrinato ligand were synthesized, and physical properties from changing the substitution groups of the synthesized materials were systematically examined. The UV-visible spectra of the synthesized materials showed maximum absorption wavelengths of about 460∼477 nm in solution state and 510∼530 nm in film state, indicating red color. It was confirmed that the extinction coefficient values (log ϵ) of all the synthesized materials are very excellent at 4.7 or above. All HOMO levels measured through cyclic voltammograms showed similar values at 5.4 through 5.5 eV, regardless of the substitution group. They were also shown to possess high potential to be applied as pigment for LCD color filter, since Tm and Td values of three synthesized materials exhibit thermal stability higher than 250°C. In film surface property, the synthesized compounds showed smooth surface overall.