INFIQC: Instituto de Investigaciones en Fisicoquímica de Córdoba (CONICET-UNC), Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
Phys Chem Chem Phys. 2019 Jan 23;21(4):1797-1804. doi: 10.1039/c8cp07162d.
The competition between dissociative photodetachment and photodissociation of cold benzoate and naphthoate anions was studied through measurement of the kinetic energy of the neutral fragments and intact parent benzoyloxy and naphtoyloxy radicals as well as by detecting the anionic fragments whenever they are produced. For the benzoate anion, there is no ionic photodissociation and the radical dissociation occurs near the vertical photodetachment energy. This is in agreement with DFT calculations showing that the dissociation energy in CO2 and C6H5˙ is very low. The dissociation barrier can be deduced from experimental results and calculations to be (0.7 ± 0.1) eV, which makes the benzoyloxyradical C6H5COO˙ very unstable, although more stable than the acetyloxy radical. In the case of naphthoate, the observation of negative fragments at low excitation energies demonstrates the opening of the ionic photodissociation channel in the excited state of the naphthoate anion, whose yield decreases at higher energies when the dissociative photodetachment channel opens.
通过测量中性碎片的动能以及完整的母体苯氧自由基和萘氧自由基，并在产生阴离子碎片时检测到它们，研究了低温苯甲酸根和萘酸根阴离子的离解光解和光解竞争。对于苯甲酸根阴离子，没有离子光解，自由基解离发生在垂直光解能附近。这与 DFT 计算结果一致，表明 CO2 和 C6H5˙中的解离能非常低。可以从实验结果和计算中推断出解离势垒为（0.7±0.1）eV，这使得苯氧自由基 C6H5COO˙非常不稳定，尽管比乙酰氧基自由基稳定。对于萘酸根，在低激发能下观察到负碎片表明萘酸根阴离子在激发态下打开了离子光解通道，当离解光解通道打开时，其产率在较高能量下降低。
