Triphenyl moieties as building blocks for obtaining molecular glasses with nonlinear optical activity
作者:Kaspars Traskovskis、Igors Mihailovs、Andrejs Tokmakovs、Andrejs Jurgis、Valdis Kokars、Martins Rutkis
DOI:10.1039/c2jm30861d
日期:——
The incorporation of trityl and triphenylsilyl groups into low molecular weight molecules allows the formation of stable molecular glasses. A series of materials based on the N-phenyldiethanolamine core was synthesized bearing different azobenzenes and benzylydene-1,3-indandione as active chromophores. Molecular hyperpolarizability of the synthesized compounds was calculated by a restricted Hartree–Fock method with basis 6-31G(d,p) and measured in solutions by hyper-Rayleigh scattering. Non-linear optical (NLO) activity of the thin glassy films was confirmed after a corona poling procedure. Thermal sustainability of the NLO response of up to 85 °C was achieved. Quantum chemical calculations of the compounds revealed increased steric bulk and conformational freedom of the triphenylsilyl moiety. While the presence of the triphenylsilyl group results in more stable glasses and increased material nonlinearity, in the case of trityl groups, measured glass transition temperatures are higher.
将三苯甲基和三苯硅基引入低分子量分子中,能够形成稳定的分子玻璃。合成了一系列基于N-苯基二乙醇胺核心的材料,这些材料带有不同的偶氮苯和苯甲亚基-1,3-茚二酮作为活性发色团。通过限制性的Hartree-Fock方法和6-31G(d,p)基组计算了合成化合物的分子超极化率,并通过超Rayleigh散射在溶液中进行了测量。经过电晕极化处理后,确认了薄玻璃态膜的非线性光学(NLO)活性。实现了高达85°C的热稳定性NLO响应。对化合物进行的量子化学计算揭示了三苯硅基部分的空间体积增加和构象自由度提高。虽然三苯硅基团的存在导致更稳定的玻璃和材料非线性增强,但对于三苯甲基团,测得的玻璃化转变温度更高。