Octupolar merocyanine dyes: a new class of nonlinear optical chromophores.
A set of new octupolar merocyanine chromophores was designed and synthesized. These compounds were prepared from the reaction of 1,3,5-triformyl-2,4,6-trihydroxybenzene with heterocyclic nucleophiles. Octupolar dyes were formed exclusively in their open-dye form. The one- and two-photon-absorption spectra of the dyes consist of two bands: The long-wavelength band in the two-photon absorption spectrum (a few hundreds GM above 1000 nm) matches well with the intense, long-wavelength-absorption band that is located in the visible region in the linear spectrum. Interestingly, an additional, much-more-intense TPA band in the NIR region is observed at higher energy, which corresponds to a weakly allowed one-photon electronic transition. Changing the peripheral heterocyclic moieties allows tuning of the optical properties to approach the cyanine limit (i.e., polymethine state), thus resulting in a red-shift of the low-energy one-photon-absorption band as well as to the rise of an intense two-photon-absorption band in the NIR region. To the best of our knowledge, this is the first synthesis and TPA characterization of octupolar merocyanine chromophores with typical low-bond-length alternation.
Institute of Organic Chemistry of the Polish Academy of Sciences, 44/52 Kasprzaka Str., 01-224 Warsaw, Poland.
Yevgen M
YM
Poronik
Vincent
V
Hugues
Mireille
M
Blanchard-Desce
Daniel T
DT
Gryko
D000042:Absorption; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D010777:Photochemistry; D017785:Photons; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D019265:Spectroscopy, Near-Infrared
D005456:Fluorescent Dyes; D006571:Heterocyclic Compounds; D011744:Pyrimidinones; C003954:merocyanine dye