Centro de Química, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
LAQV and Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Molecules. 2018 Nov 18;23(11):3014. doi: 10.3390/molecules23113014.
A series of π-conjugated molecules, based on pyridazine and thiophene heterocycles ⁻, were synthesized using commercially, or readily available, coupling components, through a palladium catalyzed Suzuki-Miyaura cross-coupling reaction. The electron-deficient pyridazine heterocycle was functionalized by a thiophene electron-rich heterocycle at position six, and different (hetero)aromatic moieties (phenyl, thienyl, furanyl) were functionalized with electron acceptor groups at position three. Density Functional Theory (DFT) calculations were carried out to obtain information on the conformation, electronic structure, electron distribution, dipolar moment, and molecular nonlinear response of the synthesized push-pull pyridazine derivatives. Hyper-Rayleigh scattering in 1,4-dioxane solutions, using a fundamental wavelength of 1064 nm, was used to evaluate their second-order nonlinear optical properties. The thienylpyridazine functionalized with the cyano-phenyl moiety exhibited the largest first hyperpolarizability ( = 175 × 10 esu, using the T convention) indicating its potential as a second harmonic generation (SHG) chromophore.
一系列基于哒嗪和噻吩杂环的π共轭分子 ⁻ ，通过钯催化的 Suzuki-Miyaura 交叉偶联反应，使用商业上或容易获得的偶联组件合成。缺电子的哒嗪杂环在第六位被富电子噻吩杂环官能化，不同的（杂）芳族部分（苯基、噻吩基、呋喃基）在第三位被电子受体基团官能化。进行密度泛函理论（DFT）计算以获得有关合成推拉哒嗪衍生物的构象、电子结构、电子分布、偶极矩和分子非线性响应的信息。使用 1064nm 的基频，在 1,4-二恶烷溶液中进行超瑞利散射，以评估它们的二阶非线性光学性质。用氰基苯基部分官能化的噻吩哒嗪表现出最大的第一超极化率（ = 175 × 10 esu，使用 T 公约），表明其有作为二次谐波产生（SHG）发色团的潜力。
