Second-Order Optical Nonlinearity of Novel Methacrylate Polymer with Pendant Disazo Dye Chromophore Containing a Perfluorobutylsulfonyl Group

Abstract

KEY WORDSNonlinear Optics (NLO) / Second-Order Nonlinear Optical Coefficient (d33) / Second Harmonic Generation (SHG) / Perfluorobutylsulfonyl / Disazo Dye / Relaxation Behavior / Potential applications like optical communications and electrooptics have motivated researchers to flourish the area of nonlinear optics (NLO). 1 -4 To get a large second-order nonlinear optical coefficient (d 33 ), dyes terminated with strong electron-withdrawing and donating groups at both the ends of the molecule separated by a n-electron conjugated system find better position. 5 -9 Efforts are also being made to improve the relaxation behavior of the chromophore after poling. The strong electron-withdrawing nature of the perfluorobutylsulfonyl group has been reported in chromophore design for NLO. 10 -12 In our previous report, 13 disazo dyes having a perfluorobutylsulfonyl group doped in polycarbonate (PC) and poly(methyl methacrylate) (PMMA) exhibited a large d 33 value and slow relaxation behavior.Based on these results, in this note, we wish to report second-order optical nonlinearity of novel methacrylate polymer with pendant perfluorobutylsulfonyl-substituted naphthylene disazo dye. EXPERIMENTAL Preparations 4-[ 4-(Perfluorobutylsulf onyl)phenylazo ]-1-naphthylamine (2)To an 20ml acetone-water solution containing 750 mg (2 mmol) of 4-(perfluorobutylsulfonyl)aniline 1 was added cone. hydrochloric acid (0.5 ml, 6 mmol). After cooling the solution to 0°C, an aqueous solution (5 ml) of sodium nitrite (138 mg, 2 mmol) was added and stirred for 2 h. To this mixture was added an aqueous buffer solution of acetic acid-sodium acetate of 1-naphthylamine (284 mg, 2 mmol) and stirred for 2 hat -5°C. After the reaction was completed, the resulting precipitate was filtered, rinsed with water and dried. The obtained solid was purified by column chromatography (silica gel, CH2Cl 2 ), followed by recrystallization from chloroform-hexane. Yield 50%; mp 114-115°C; 1 H NMR (CDC1 3 ): fJ 4.92 (brs, 2H), 6.86 (d, J=8.2Hz, lH), lH), lH), 7.84 (d, J= 9.4Hz, lH), 8.06 (d, J=9.4Hz, lH), 8.16 (d, J=6.7Hz, t To whom correspondence should be addressed. 4-[ 4-[ 4-(Perfluorobutylsulfonyl)phenylazo ]naphthylazo ]-N-ethyl-N-hydroxyethylaniline (3)To an acetone-ethanol-water solution (2.0: 1.0: 0.5, 30ml) of 529mg of 2 (1 mmol) was added cone. hydrochloric acid (0.25 ml, 3 mmol). After cooling the solution between O and 5°C, an aqueous solution (5 ml) of sodium nitrite (69mg, 1 mmol) was added and stirred for 6 h. To this mixture was added an acetone solution (5 ml) of 2-(N-ethylanilino )ethanol (350 mg, 2 mmol) and stirred overnight at room temperature. After the reaction was completed, the resulting precipitate was washed with water and dried. The product was purified by column chromatography (silica gel, CH 2 Cl 2 ), followed by recrystallization from chloroform-hexane. Yield 30%; mp 130°C; 1 H NMR (CDC1 3 ): fJ 1.29 (t, J=6.4Hz, 3H), 1.63 (br, lH), 3.60 (q, J=6.4Hz, 2H), 3.66 (t, J=4.6Hz, 2H), 3.91 (t, J=4.6Hz, 2H), 6.87 (d, J=7.9Hz, 2H), 2H), 7.8...

Development of polyurethanes with azo‐type chromophores for second‐order nonlinear optical applications

“…Thus, when our systems were compared with other systems with similar structures and T g values, such as poly(methyl methacrylate) (PMMA)‐ or PS‐based NLO polymers, in which hydrogen bonding does not occur, better stability was observed. A discussion of the stability of PMMA‐ and PS‐based NLO polymers can be found in the literature 47–49. Figure 9 further shows that the signal disappeared completely as the temperature rose above T g .…”

“…A discussion of the stability of PMMA-and PS-based NLO polymers can be found in the literature. [47][48][49] Figure 9 further shows that the signal disappeared completely as the temperature rose above T g . However, the same magnitude of the SHG signal was recovered from this sample after it was repoled by corona discharging, and this indicated that the NLO chromophore was not damaged after experiencing a high temperature.…”