Zhang Xu, Nimlos Mark R, Ellison G Barney, Varner Mychel E, Stanton John F
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
J Chem Phys. 2007 May 7;126(17):174308. doi: 10.1063/1.2720392.
Cis, cis-peroxynitrous acid is known to be an intermediate in atmospheric reactions between OH and NO2 as well as HOO and NO. The infrared absorption spectra of matrix-isolated cc-HOONO and cc-DOONO in argon have been observed in the range of 500-8000 cm-1. Besides the seven fundamental vibrational modes that have been assigned earlier for this molecule [Zhang et al., J. Chem. Phys. 124, 084305 (2006)], more than 50 of the overtone and combination bands have been observed for cc-HOONO and cc-DOONO. Ab initio CCSD(T)/atomic natural orbital anharmonic force field calculations were used to help guide the assignments. Based on this study of the vibrational overtone transitions of cis, cis-HOONO that go as high as 8000 cm-1 and the earlier paper on the vibrational fundamentals, we conclude that the CCSD(T)/ANO anharmonic frequencies seem to correct to +/-35 cm-1. The success of the theoretically predicted anharmonic frequencies {upsilon} in assigning overtone spectra of HOONO up to 8000 cm-1 suggests that the CCSD(T)/ANO method is producing a reliable potential energy surface for this reactive molecule.
顺式、顺式过氧亚硝酸被认为是大气中OH与NO₂以及HOO与NO反应的中间体。在500 - 8000 cm⁻¹范围内观测到了氩气基质隔离的顺式-HOONO和顺式-DOONO的红外吸收光谱。除了此前已为该分子指定的七种基本振动模式[Zhang等人，《化学物理杂志》124, 084305 (2006)]，还观测到了顺式-HOONO和顺式-DOONO的50多个泛音带和组合带。采用从头算耦合簇单双激发（CCSD(T)）/原子自然轨道非谐力场计算来辅助进行归属。基于对高达8000 cm⁻¹的顺式、顺式-HOONO振动泛音跃迁的这项研究以及之前关于振动基频的论文，我们得出结论，CCSD(T)/ANO非谐频率似乎精确到±35 cm⁻¹。理论预测的非谐频率υ在归属高达8000 cm⁻¹的HOONO泛音光谱方面的成功表明，CCSD(T)/ANO方法正在为这种反应性分子生成一个可靠的势能面。
