N2+hν→N++N+e-过程的脉冲场电离光电子-光离子符合研究：N2和N2+的键解离能

Pulsed field-ionization photoelectron-photoion coincidence study of the process N2+hnu-->N++N+e-: bond dissociation energies of N2 and N2+.

作者信息

Tang Xiaonan, Hou Yu, Ng C Y, Ruscic Branko

机构信息

Department of Chemistry, University of California, Davis, California 95616, USA.

出版信息

J Chem Phys. 2005 Aug 15;123(7):074330. doi: 10.1063/1.1995699.

DOI:10.1063/1.1995699

PMID:16229593

Abstract

We have examined the dissociative photoionization reaction N2+hnu-->N++N+e- near its threshold using the pulsed field-ionization photoelectron-photoion coincidence (PFI-PEPICO) time-of-flight (TOF) method. By examining the kinetic-energy release based on the simulation of the N+ PFI-PEPICO TOF peak profile as a function of vacuum ultraviolet photon energy and by analyzing the breakdown curves of N+ and N2+, we have determined the 0-K threshold or appearance energy (AE) of this reaction to be 24.2884+/-0.0010 eV. Using this 0-K AE, together with known ionization energies of N and N2, results in more precise values for the 0-K bond dissociation energies of N-N (9.7543+/-0.0010 eV) and N-N+ (8.7076+/-0.0010 eV) and the 0-K heats of formation for N (112.469+/-0.012 kcal/mol) and N+ (447.634+/-0.012 kcal/mol).

摘要

我们使用脉冲场电离光电子-光离子符合（PFI-PEPICO）飞行时间（TOF）方法，在接近阈值的情况下研究了离解光电离反应N2+hnu-->N++N+e-。通过基于N+ PFI-PEPICO TOF峰形模拟作为真空紫外光子能量的函数来检查动能释放，并通过分析N+和N2+的击穿曲线，我们确定该反应的0-K阈值或出现能量（AE）为24.2884±0.0010 eV。使用这个0-K AE，结合已知的N和N2的电离能，得到了更精确的N-N（9.7543±0.0010 eV）和N-N+（8.7076±0.0010 eV）的0-K键离解能以及N（112.469±0.012 kcal/mol）和N+（447.634±0.012 kcal/mol）的0-K生成热的值。