Synthesis of Aryl-Substituted 1,3-Butadiones

Visible‐Light Excitation of Infrared Lanthanide Luminescence via Intra‐Ligand Charge‐Transfer State in 1,3‐Diketonates Containing Push‐Pull Chromophores

“…One may consider HL-NMe 2 as an analogue of Michler's ketone (Scheme 2) -a push-pull chromophore, which was shown to be an excellent sensitizer of lanthanide luminescence. [27] In fact, similar 1,3-diketones containing 4-(dialkyl-or diarylamino)phenyl groups reported in the literature [15,26,[28][29][30][31][32] also display a low-energy absorption band which was shown by spectroscopic measurements [26,28] and calculations [31] to be of a charge-transfer nature. In comparison, the lowest-energy absorption transition in dibenzoylmethane and bis(p-nitrobenzoyl)methane -model 1,3-diketones which do not contain donor groups -occurs in the onset of the UV range at 352 nm and 362 nm, [17] .…”