Acido- and Phototriggered NLO Properties Enhancement

Abstract

In this paper, acido- and phototriggered enhancement of the nonlinear optical (NLO) properties are achieved by combining the 10-(2-arylethenyl)indolino[2,1-b]oxazolidine unit with various styrylic residues. The synthetic pathway allows the preparation of phenyl, naphthyl, anthryl, and phenanthryl derivatives, which have been shown to display photochromic and acidochromic behavior at ambient temperature. The multiaddressable molecular switches are characterized by a large contrast of the NLO response along the reversible transformations. Hyper-Rayleigh scattering (HRS) experiments clearly indicate the strong influence of the electrodonating substituent borne by the aromatic system. Theoretical calculations have been performed for representative molecules showing a good agreement with the experimental hyperpolarizabilities. This enables a better understanding of the NLO responses in terms of structural and electronic parameters for both closed and protonated open forms.

Hydrochromic molecular switches for water-jet rewritable paper

“…1a). 1-10 were synthesized 19,32 with a modified four-step procedure by using phenylhydrazines as starting materials, as shown in Fig. 2.…”

Indolinooxazolidine: A Versatile Switchable Unit

“…According to previous Scheme 2. Synthetic route to 10-(2-(5′-(Methylthio)-2,2′-bithiophen)-5-yl)ethenyl)-indolino[2,1-b]oxazolidine Derivatives bTBoX (4a) and Me-bTBoX (4b) studies, 30,45 this drastic spectral change is explained by the oxazolidine ring-opening which, on one hand increases the length of π-conjugated system and on the other hand, induces the generation of charge transfer between the electron donating thiomethyl susbtituent and the electron withdrawing indolenium moiety. The neutralization of the media by simple addition of any base (K 2 CO 3 or NEt 3 ) induces the oxazolidine ring closure and allows us to recover the original spectrum.…”

Syntheses, Crystal Structures and Photophysical Measurements of Phosphite‐Substituted Schiff Base and Azobenzene Li­gands

“…[1][2][3][4][5][6][7][8] Because the success of many of these applications depends on the strength of the second-order NLO material, there has been a significant effort to improve the performance of second-order NLO organic and organometallic materials by designing molecules with large first hyperpolarizibilities (β). [9][10][11][12][13][14][15][16][17][18][19][20] Many of the most promising secondorder NLO materials are dipolar aromatic molecules possessing an electron donor and acceptor group, because larger second-order optical nonlinearities can arise from the intramolecular charge transfer between the opposite groups through their π-conjugated systems. [21][22][23][24][25] Organometallic and coordination metal complexes represent a growing class of second-order NLO compounds that offer additional flexibility and tunability.…”