Carbon dots (C-dots) are photoluminescent nanoparticles with less than 10 nm in size. Today, many studies are performed to exploit the photoluminescence (PL) property of carbon dots, and our focus in this study is to estimate the dipole moment of carbon dots. For reaching our aims, C-dots were synthesized and dissolved in the different solvents. Carbon dots with intense photoluminescence properties have been synthesized by a one-step hydrothermal method from a carbon bio-source. In this research, we report on the effect of aprotic solvents on absorption and fluorescence spectra and dipole moments of C-dots dispersed in a range of many aprotic solvents with various polarity and dielectric constant at room temperature. The change in the value of dipole moment was estimated by using the Stokes shifts. The difference between the dipole moment of the excited state and the ground state was shown using an extended form of Lippert equations by Kawski and co-workers. The values found for μg = 1.077 D, and μe = 3.157 D, as well as the change in the dipole moments. The results showed that the dipole moment of the excited state is more than the ground state, indicating a high density and redistribution of electrons in the excited state. Finally, the quantum yield of C-dots in the eclectic aprotic solvents was communicated and discussed.

中文翻译：

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溶剂对碳点吸收和发射光谱的影响：评估基态和激发态偶极矩

碳点 (C-dots) 是尺寸小于 10 nm 的光致发光纳米颗粒。今天，进行了许多研究以利用碳点的光致发光 (PL) 特性，我们在这项研究中的重点是估计碳点的偶极矩。为了达到我们的目标，C-dots 被合成并溶解在不同的溶剂中。已经通过一步水热法从碳生物源合成了具有强烈光致发光特性的碳点。在这项研究中，我们报告了非质子溶剂对室温下分散在具有各种极性和介电常数的多种非质子溶剂中的碳点的吸收和荧光光谱以及偶极矩的影响。通过使用斯托克斯位移估计偶极矩值的变化。Kawski 及其同事使用 Lippert 方程的扩展形式显示了激发态和基态偶极矩之间的差异。发现的 μg = 1.077 D 和 μe = 3.157 D 的值，以及偶极矩的变化。结果表明，激发态的偶极矩大于基态，表明激发态的电子密度高且重新分布。最后，交流和讨论了折衷非质子溶剂中碳点的量子产率。表明激发态电子的高密度和重新分布。最后，交流和讨论了折衷非质子溶剂中碳点的量子产率。表明激发态电子的高密度和重新分布。最后，交流和讨论了折衷非质子溶剂中碳点的量子产率。