Tetracyanobutadienyl-Based Nonlinear Optical Dendronized Hyperbranched Polymer Synthesized via [2+2] Cycloaddition Polymer Postfunctionalization.

Dendronized hyperbranched polymers (DHPs) can provide advantages for both hyperbranched polymers and dendrimers, making them a promising structure platform for high-performance second-order nonlinear optical (NLO) materials. Herein, a new A 3 +B 2 -type DHP (HP2) is reported through facile and efficient [2+2] cycloaddition polymer postfunctionalization, in which tetracyanobutadienyl-based moieties are introduced as the main chromophores while isophorone-bridged moieties serve as the isolation chromophores. Benefiting from this unique hyperbranched structure design, the measured second-harmonic generation coefficient of HP2 can reach up to 96.6 pm V -1 with high thermal stability, making it a good material candidate for second-order NLO applications.