A new series of four D–A–D configured conjugated oligomers with H–type structure, possessing two thiophene–imidazo [2,1-b][1,3,4]thiadiazole branches and thiophene (TIT), thiophene–1,3,4-oxadiazole–thiophene (TITO), thiazolo [5,4-d]thiazole (TITz), phenyl–thiazolo [5,4-d]thiazole–phenyl (TIPTz) units as central core moieties were efficiently synthesized. These core moieties were specifically selected to increase the planarity, rigidity, stability, extend the π–conjugation and to understand the influence of central core on nonlinear absorption coefficient (β_eff) and optical limiting behavior of the synthesized oligomers. The structure-property relationships of these oligomers were established by the optical absorption (UV–Vis), electrochemical (CV) and theoretical (DFT) studies. The “effective two–photon absorption” of oligomers was confirmed by single–beam Z–scan analysis. The exceptional increase in nonlinear response was achieved with the oligomers TITO and TIPTz with nonlinear absorption coefficient (β_eff) of 1.62 and 2.71 × 10⁻¹⁰ m W⁻¹, and limiting thresholds of 6.02 and 3.14 J cm⁻², respectively, which suggest that these oligomers could be potent materials for practical applications in laser photonics.

一系列新的四个由D–A–D构型的H型结构共轭低聚物，具有两个噻吩–咪唑并[2,1- b ] [1,3,4]噻二唑分支和噻吩（TIT），噻吩–1，有效地合成了3,4-恶二唑–噻吩（TITO），噻唑并[5,4- d ]噻唑（TITz），苯基噻唑并[5,4- d ]噻唑–苯基（TIPTz）单元。这些核心部分是专门选择以增加平面度，刚性，稳定性，延长该π共轭和理解核心中央非线性吸收系数的影响（β _EFF）和合成低聚物的光学极限行为。这些低聚物的结构-性质关系是通过光吸收（UV-Vis），电化学（CV）和理论（DFT）研究建立的。单光束Z扫描分析证实了低聚物的“有效两光子吸收”。在非线性响应异常增加与所取得的低聚物TITO和TIPTz具有非线性的吸收系数（β _EFF的1.62）和2.71×10 ^-10 米w ^ ^-1，和6.02和3.14Ĵ厘米的极限阈值^-2，分别，这这些低聚物可能是激光光子学中实际应用的有效材料。