[n]-Polyenovanillins (n = 1-6) as New Push-Pull Polyenes for Nonlinear Optics: Synthesis, Structural Studies, and Experimental and Theoretical Investigation of Their Spectroscopic Proper
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- 作者：Thierry Brotin ; Chantal Andraud ; Isabelle Ledoux ; Sophie Brasselet ; Joseph Zyss ; Monique Perrin ; Alain Thozet ; and André ; Collet
- 刊名：Chemistry of Materials
- 出版年：1996
- 出版时间：April 1996
- 年：1996
- 卷：8
- 期：4
- 页码：890 - 906
- 全文大小：541K
- 年卷期：v.8,no.4(April 1996)
- ISSN：1520-5002
文摘
We describe the synthesis and quadratic hyperpolarizabilityproperties of [n]-polyenovanillins, a new family of push-pull polyenes deriving from vanillin,thiovanillin, andisothiovanillin. Twenty-five [n]-polyenovanillins ofstructure3,4-(RO;R'S)C6H4(CH=CH)nCH=O [with n = 1-6 and R, R' = Me orn-Bu] were synthesized by using aWittig-Hornerpolyvinylogation methodology, and the structure of one of these wasestablished by single-crystal X-ray crystallography. The UV-vis absorption andfluorescence spectra of thesepolyenovanillins were recorded and interpreted in light of CNDO/Scalculations that allowedthe identification of the different transitions. EFISHmeasurements provided
up to350 × 10-30 esu (for 14,n = 6) with an exponential increase of the quadratichyperpolarizability with the conjugation length. These data weresatisfactorily interpreted by meansof a CNDO/S/NLO method which provided information as to the relativeorientation of thedipole moment 
and 
vec, the vector part of thehyperpolarizability tensor. In the sulfur-substituted series, there is a significant divergence between theorientation of and vec,which in turn leads to an underestimation of in the EFISH method.The calculation alsorevealed that when the length of the polyenic chain increases, thecharge transfer from thedonor toward the acceptor actually tends to concentrate on the polyenicchain rather thanon the aldehyde group.
up to350 × 10-30 esu (for 14,n = 6) with an exponential increase of the quadratichyperpolarizability with the conjugation length. These data weresatisfactorily interpreted by meansof a CNDO/S/NLO method which provided information as to the relativeorientation of thedipole moment and vec, the vector part of thehyperpolarizability tensor. In the sulfur-substituted series, there is a significant divergence between theorientation of and vec,which in turn leads to an underestimation of in the EFISH method.The calculation alsorevealed that when the length of the polyenic chain increases, thecharge transfer from thedonor toward the acceptor actually tends to concentrate on the polyenicchain rather thanon the aldehyde group.