The second-order nonlinear optical properties of 1,3-indandione-derived spirocyclohexadine compounds, a new class of photochromes showing sensitivity to both UV and visible lights, are investigated by means of density functional theory. The calculations predict that these compounds should display a large first hyperpolarizability variation upon commutation between their cyclic spiropyran and their merocyanine form. We also show that significant enhancement of the NLO response of the merocyanine form, as well as of the NLO contrast, can be achieved by means of appropriate chemical substitution, which makes these derivatives highly appealing for potential use in photo-responsive NLO devices.

中文翻译：

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螺环己啶光致变色剂的非线性光学性质：DFT计算得出的见解†

利用密度泛函理论研究了1,3-茚满二酮衍生的螺环己二烯化合物的二阶非线性光学性质，这是一类对紫外光和可见光均敏感的新型光致变色材料。该计算预测，这些化合物在其环状螺吡喃和部花菁形式之间进行换向时应显示出较大的第一超极化率变化。我们还表明，可以通过适当的化学取代来显着增强花青素形式的NLO响应以及NLO对比度，这使得这些衍生物在光响应性NLO设备中具有潜在的吸引力。