10.1021/jo901142f.s001
Raquel Andreu
Raquel
Andreu
Laura Carrasquer
Laura
Carrasquer
Santiago Franco
Santiago
Franco
Javier Garín
Javier
Garín
Jesús Orduna
Jesús
Orduna
Natalia Martínez de Baroja
Natalia
Martínez de Baroja
Raquel Alicante
Raquel
Alicante
Belén Villacampa
Belén
Villacampa
Magali Allain
Magali
Allain
4<i>H</i>-Pyran-4-ylidenes: Strong Proaromatic Donors for Organic Nonlinear Optical Chromophores
American Chemical Society
2009
nonlinearitie
polyenic spacer
moiety
zwitterionic ground states
NMR studies
Proaromatic Donors
esu
donor
compound
μβ1907 values
pyran derivatives
data
acceptor
proaromaticity
diffraction
Organic Nonlinear Optical ChromophoresMerocyanines
2009-09-04 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/4_i_H_i_Pyran_4_ylidenes_Strong_Proaromatic_Donors_for_Organic_Nonlinear_Optical_Chromophores/2830243
Merocyanines where a polyenic spacer separates a 4<i>H</i>-pyran-4-ylidene moiety and different strong organic acceptors have been synthesized. According to NMR studies and X-ray diffraction data, these compounds have weakly alternated structures and remarkably zwitterionic ground states, with a partial aromatic character that is compared to those of other pyran derivatives. The proaromaticity of the 4<i>H</i>-pyran-4-ylidene donor lies behind the cyanine-like behavior and low (positive or negative) second-order optical nonlinearities of the shorter derivatives. On the other hand, lengthening the π-spacer gives rise to rapidly increasing μβ<sub>1907</sub> values up to 17,400 × 10<sup>−48</sup> esu.