Synthesis and two-photon absorption properties of truxene-cored chromophores with functionalized pyrazine units fused as the end-groups

A new set of model chromophores derived from a truxene core fused with varied number and size of functionalized pyrazine units was designed and synthesized for the tentative exploration of possible connections between the molecular structure and their linear/nonlinear optical properties. The initial experimental results have indicated that these model compounds not only possess strong and widely dispersed two-photon absorption (2 PA) within the near-IR region but also show the ascending overall 2 PA when the molecular structure varies with increase in complexity and molecular weight, which implies that both the number of branches and the size of π-framework are important factors to the molecular 2 PA in this model chromophore system. On the other hand, the studied model chromophores also manifest very good photostability within their two-photon active spectral region even under a prolonged irradiation of IR laser pulses. In addition, a representative chromophore is selected to demonstrate optical power-limiting and power-stabilization performance against nanosecond laser pulses.