Albeck Yishai, Lunny Katharine G, Benitez Yanice, Shin Ashley J, Strasser Daniel, Continetti Robert E
Institute of Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel.
Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0340, USA.
Angew Chem Int Ed Engl. 2019 Apr 8;58(16):5312-5315. doi: 10.1002/anie.201900386. Epub 2019 Mar 18.
The photoexcitation of cold oxyallyl anions was studied below the adiabatic detachment threshold at a photon energy of 1.60 eV. Photodetachment was observed through two product channels, delayed electron emission from a long-lived anionic state and dissociative photodetachment via absorption of a second photon. The former produced stable neutral C H O, while the latter resulted in the concerted elimination of CO+C H products. The neutral oxyallyl singlet state has a barrier-free route to cyclopropanone as well as zwitterionic character with a large charge separation and dipole moment. The role of long-lived dipole-bound resonances built on the singlet state below the detachment threshold is discussed. These results provide one of the first observations of delayed photoemission in a small cold molecular radical anion, a consequence of the complex electronic structure of the neutral diradical, and provide an example of resonance-mediated control of the photodissociation processes.
在光子能量为1.60 eV的情况下，对冷氧烯丙基阴离子的光激发进行了低于绝热脱附阈值的研究。通过两个产物通道观察到光脱附，即从长寿命阴离子态延迟发射电子以及通过吸收第二个光子进行解离光脱附。前者产生稳定的中性C H O，而后者导致协同消除CO + C H产物。中性氧烯丙基单重态具有一条通向环丙酮的无障碍路径以及具有大电荷分离和偶极矩的两性离子特征。讨论了在脱附阈值以下基于单重态构建的长寿命偶极束缚共振的作用。这些结果首次观察到了小冷分子自由基阴离子中的延迟光发射，这是中性双自由基复杂电子结构的结果，并提供了一个共振介导控制光解离过程的例子。
