712273-65-9Relevant academic research and scientific papers
4H-pyran-4-ylidenes: Strong proaromatic donors for organic nonlinear optical chromophores
Andreu, Raquel,Carrasquer, Laura,Franco, Santiago,Garin, Javier,Orduna, Jesus,De Baroja, Natalia Martinez,Alicante, Raquel,Villacampa, Belen,Allain, Magali
scheme or table, p. 6647 - 6657 (2009/12/31)
(Chemical Equation Presented) Merocyanines where a polyenic spacer separates a 4H-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 alterna
Synthesis and linear/nonlinear optical properties of a new class of 'RHS' NLO chromophore
Kay, Andrew J.,Woolhouse, Anthony D.,Zhao, Yuxia,Clays, Koen
, p. 1321 - 1330 (2007/10/03)
Examples of a new class of zwitterionic, "right-hand side" merocyanines containing a cyanodicyanomethylidenedihydrofuran electron acceptor have been prepared. As well as allowing for the facile synthesis of these chromophores, our synthetic methodology enables considerable variation in both the donor moiety as well as the extent of conjugation between the donor and acceptor systems. As expected, all of these "right-hand side" systems are negatively solvatochromic, with the difference between λ max (polar vs. nonpolar solvents) increasing with the extent of conjugation. In accord with expectations, hyper-Raleigh scattering (HRS) measurements confirm that molecules with the greatest conjugation pathway (for e.g. 21c, 23c) have the largest first hyperpolarisabilites, βo. In addition, our HRS evaluation indicates that the 4-quinolinylidene donor nucleus is superior to both the 4-pyridinylidene and benzothiazolylidene systems. The figures of merit, μ(calc). βo(measured), that we obtain for some of these compounds, are of a similar magnitude to the best "left hand side" examples reported in the literature. In order to demonstrate the versatility of our synthetic technique, representative polymer-tetherable derivatives of these compounds have been prepared, as have the corresponding TDI-based polyurethanes.
