Study on the synthesis and third-order nonlinear optical properties of D-A poly-quinacridone optical materials

Abstract Quinacridone stands out among many optical materials, because it possesses a large π-conjugated system, remarkable photothermal stability, excellent semiconductor property, and easy modification at multiple active sites of parent molecule. In this paper, the functionalized D-A poly-quinacridone derivatives have been achieved in good yields via Suzuki cross-coupling reactions, two of polymers, PQA-A and PQA-B , were mainly composed of quinacridone and dicyanovinyl-substituted quinacridone, respectively. The polymers have multiple broad absorption band at a wavelength of 230–600 nm. Polymer PQA-B showed a good photoluminescence quantum yield in the luminescence spectra, which can attributed to the immobilization of dicyanovinyl-substituted quinacridone in the polymer and limited the inversion between its structures. The χ (3) value of polymer PQA-B was 15.456 × 10 −12  esu, which is up to 5 times than that of monomer material measured by Z-scan technique. PQA-A not only had the large third-order NLO response ( χ (3)  = 9.820 × 10 −12  esu), but had the good thermal stability (T d  = 402 °C), and these good performances will make it more attractive for applications in integrated NLO devices. Our results can be used to develop an efficient design strategy for NLO materials.