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未结合吡啶单体中环境光诱导的分子间库仑衰减
作者:小柯机器人 发布时间:2022/8/5 18:36:04

印度马德拉斯理工学院Aravind, G.团队揭示了未结合吡啶单体中环境光诱导的分子间库仑衰减。相关研究成果发表在2022年7月31日出版的《自然—化学》。

分子间库仑衰减(ICD)是光激发分子通过电离其相邻分子而松弛的过程。当分子间相互作用活跃时,ICD是有效的,因此它只在弱束缚系统中观察到,如团簇和氢键系统。

该文中,研究人员报告了在环境光强度下激发的未结合分子之间的有效ICD。在气相吡啶单体的光激发下,在远低于电离阈值和低激光强度下,检测到母体阳离子和比母体阳离子重的阳离子。慢电子的各向同性发射揭示了ICD是潜在的过程。在无界吡啶单体中的π–π*激发触发了它们之间的缔合相互作用,这导致了高效的三中心ICD。三个吡啶中心的分子缔合产生的阳离子通过破碎松弛。

这种在环境光下低于阈值的电离对于理解辐射损伤和天体化学有着重要意义。

附:英文原文

Title: Ambient-light-induced intermolecular Coulombic decay in unbound pyridine monomers

Author: Barik, Saroj, Dutta, Saurav, Behera, Nihar Ranjan, Kushawaha, Rajesh Kumar, Sajeev, Y., Aravind, G.

Issue&Volume: 2022-07-31

Abstract: Intermolecular Coulombic decay (ICD) is a process whereby photoexcited molecules relax by ionizing their neighbouring molecules. ICD is efficient when intermolecular interactions are active and consequently it is observed only in weakly bound systems, such as clusters and hydrogen-bonded systems. Here we report an efficient ICD between unbound molecules excited at ambient-light intensities. On the photoexcitation of gas-phase pyridine monomers, well below the ionization threshold and at low laser intensities, we detected the parent and heavier-than-parent cations. The isotropic emission of slow electrons revealed ICD as the underlying process. π–π* excitation in unbounded pyridine monomers triggered an associative interaction between them, which leads to an efficient three-centre ICD. The cation resulting from the molecular association of the three pyridine centres relaxed through fragmentation. This below-threshold ionization under ambient light has implications for the understanding of radiation damage and astrochemistry.

DOI: 10.1038/s41557-022-01002-2

Source: https://www.nature.com/articles/s41557-022-01002-2

期刊信息

Nature Chemistry:《自然—化学》,创刊于2009年。隶属于施普林格·自然出版集团,最新IF:21.687
官方网址:https://www.nature.com/nchem/
投稿链接:https://mts-nchem.nature.com/cgi-bin/main.plex