Campargue A, Barbe A, De Backer-Barilly M-R, Tyuterev Vl G, Kassi S
Laboratoire de Spectrométrie Physique, UMR CNRS 5588, Université Joseph Fourier, BP 87-38402, Saint Martin d'Hères Cedex, France.
Phys Chem Chem Phys. 2008 May 28;10(20):2925-46. doi: 10.1039/b719773j. Epub 2008 Mar 19.
Weak vibrational bands of (16)O(3) could be detected in the 5850-7030 cm(-1) spectral region by CW-cavity ring down spectroscopy using a set of fibered DFB diode lasers. As a result of the high sensitivity (noise equivalent absorption alpha(min) approximately 3 x 10(-10) cm(-1)), bands reaching a total of 16 upper vibrational states have been previously reported in selected spectral regions. In the present report, the analysis of the whole investigated region is completed by new recordings in three spectral regions which have allowed: (i) a refined analysis of the nu(1) + 3nu(2) + 3nu(3) band from new spectra in the 5850-5900 cm(-1) region; (ii) an important extension of the assignments of the 2nu(1)+5nu(3) and 4nu(1) + 2nu(2) + nu(3) bands in the 6500-6600 cm(-1) region, previously recorded by frequency modulation diode laser spectroscopy. The rovibrational assignments of the weak 4nu(1) + 2nu(2) + nu(3) band were fully confirmed by the new observation of the 4nu(1) + 2nu(2) + nu(3)- nu(2) hot band near 5866.9 cm(-1) reaching the same upper state; (iii) the observation and modelling of three A-type bands at 6895.51, 6981.87 and 6990.07 cm(-1) corresponding to the highest excited vibrational bands of ozone detected so far at high resolution. The upper vibrational states were assigned by comparison of their energy values with calculated values obtained from the ground state potential energy surface of (16)O(3). The vibrational mixing and consequently the ambiguities in the vibrational labelling are discussed. For each band or set of interacting bands, the spectroscopic parameters were determined from a fit of the corresponding line positions in the frame of the effective Hamiltonian (EH) model. A set of selected absolute line intensities was measured and used to derive the parameters of the effective transition moment operator. The exhaustive review of the previous observations gathered with the present results is presented and discussed. It leads to a total number of 3863 energy levels belonging to 21 vibrational states and corresponding to 7315 transitions. In the considered spectral region corresponding to up to 82% of the dissociation energy, the increasing importance of the "dark" states is illustrated by the occurrence of frequent rovibrational perturbations and the observation of many weak lines still unassigned.
利用一组光纤分布反馈（DFB）二极管激光器，通过连续波腔衰荡光谱技术，可在5850 - 7030厘米⁻¹光谱区域检测到¹⁶O₃的弱振动带。由于具有高灵敏度（噪声等效吸收α(min)约为3×10⁻¹⁰厘米⁻¹），先前已在选定光谱区域报道了总共涉及16个高振动态的谱带。在本报告中，通过在三个光谱区域的新记录完成了对整个研究区域的分析，这些记录使得：（i）对5850 - 5900厘米⁻¹区域新光谱中的ν₁ + 3ν₂ + 3ν₃谱带进行了精细分析；（ii）对6500 - 6600厘米⁻¹区域中2ν₁ + 5ν₃和4ν₁ + 2ν₂ + ν₃谱带的归属进行了重要扩展，该区域先前已通过频率调制二极管激光光谱进行记录。在5866.9厘米⁻¹附近对4ν₁ + 2ν₂ + ν₃ - ν₂热带的新观测到达相同的高态，从而充分证实了弱4ν₁ + 2ν₂ + ν₃谱带的振转归属；（iii）在6895.51、6981.87和6990.07厘米⁻¹处观测并模拟了三个A类谱带，它们对应于迄今为止在高分辨率下检测到的臭氧的最高激发振动谱带。通过将其能量值与从¹⁶O₃基态势能面获得的计算值进行比较，确定了高振动态。讨论了振动混合以及由此导致的振动标记中的模糊性。对于每个谱带或相互作用的谱带组，在有效哈密顿量（EH）模型框架内，通过对相应谱线位置的拟合确定了光谱参数。测量了一组选定的绝对谱线强度，并用于推导有效跃迁矩算符的参数。对先前观测结果与当前结果进行了详尽综述并展开讨论。这导致总共3863个能级，属于21个振动态，对应7315个跃迁。在对应高达82%离解能的考虑光谱区域中，频繁的振转微扰的出现以及许多未归属的弱线的观测说明了“暗”态的重要性日益增加。
