The chemistry within the interstellar medium (ISM) is notably influenced by the interplay between kinetics and photochemical processes, which play significant roles in both the formation and destruction of molecular species. This study focuses on theoretical investigations of Al₂O photochemistry, aiming to elucidate the mechanisms underlying the production of AlO and Al in the VY-CMa star. Utilizing advanced theoretical methodologies, we explore the lowest electronic states with singlet and triplet spin multiplicities in linear Al₂O. We investigated the photostability of Al₂O in the near UV‒Vis region, revealing the low likelihood of photodissociation and photoconversion while suggesting the plausibility of fluorescence and phosphorescence phenomena. Calculations also identify three prominent peaks in the UV range at 261.5, 206.2, and 199 nm. Finally, Al₂O is predicted to be photostable and cannot be the parent molecule of the diatomic AlO or even the astrochemical reservoir of atomic aluminum. These results contribute to improving the astronomical models in simulating aluminum chemistry in the ISM.

中文翻译：

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 Al2O光化学


星际介质（ISM）内的化学反应明显受到动力学和光化学过程之间相互作用的影响，这在分子物种的形成和破坏中发挥着重要作用。本研究侧重于Al ₂ O光化学的理论研究，旨在阐明VY-CMa星中Al2O和Al产生的机制。利用先进的理论方法，我们探索了线性 Al ₂ O 中具有单重态和三重态自旋多重性的最低电子态。我们研究了 Al ₂ O 在近紫外-可见光区域的光稳定性，揭示了光解离和光转换的可能性较低，同时提出了荧光和磷光现象的合理性。计算还确定了 UV 范围内 261.5、206.2 和 199 nm 的三个突出峰。最后，Al ₂ O 被预测具有光稳定性，并且不可能是双原子 Al2O 的母体分子，甚至不可能是原子铝的天体化学库。这些结果有助于改进 ISM 中模拟铝化学的天文模型。