Organic main-chain nonlinear optical polymers. 1. Copolymerization of bis(arenecarboxaldehydes) and bis(cyanoacetate) monomers via the Knoevenagel condensation

Synthesis and characterization of accordion main-chain azo-dye polymers for second-order optical non-linearity

“…To prepare the accordion azo polymers, Knoevenagel condensation between the biscarboxaldehyde and biscyanoacetate comonomers was carried out in the presence of DMAP or piperidine according to the method described by Wright and co‐workers 14. 17, 18 The polymerization yields varied from 53 % to 72 %. All the polymers were of red colour and characterized by 1 H NMR (except P5 and P6 ), FTIR, UV–vis spectroscopy and thermal analysis (except P5 and P6 ).…”

Second-order non-linear optical polymers

“…Köhler et al 12,13) studied the relaxation of electric field induced polar orientation in main-chain polymers. Stenger-Smith et al 65,66) , Lindsay et al 67) , Wrigth et al 68,69) and Liu et al 70) also synthesized main-chain polymers, but the reported second-order susceptibilites were low (0.17 pm/V). A polyurethane main-chain polymer with dialkylamino sulfonyl azobenzene incorporated in the main chain was studied by Xu et al 71) They measured a d 33 (-2 x; x, x) value of 40 pm/V (T g not given, poled at 115 8C, excitation at 1 064 nm).…”

Synthesis and Characterization of Poly(pyridinium triflate)s with Alkyl and Aromatic Spacer Groups for Potential Use as Nonlinear Optic Materials

“…Of these systems, the latter is optimal because of higher chromophore density and the stability of chromophore orientation after alignment. It has been shown that superior chromophore alignment and NLO responses can be obtained by connecting the chromophores in head-to-head and tail-to-tail fashion [6,7]. In these systems, the NLO chromophores are separated by spacers and can fold into an accordion-type structure (scheme 1).…”