Synthesis, Characterization and Unusual Near-Infrared Luminescence of 1,1,4,4-Tetracyanobutadienes

Two 1,1,4,4-tetracyanobutadiene (TCBD) derivatives were prepared by [2+2]cycloaddition-retroelectrocyclization from ynamides bearing either a pyrene (1) or a perylene unit (2). In addition to panchromatic absorptions in 2, in the solid state, both compounds unexpectedly display NIR photoluminescence that could be detected up to about 1350 nm.