A theoretical investigation of the vibrational states of HCO2- and its isotopomers.
A theoretical investigation of the vibrational states of HCO2- and its isotopomers.
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HCO2- 及其同位素振动状态的理论研究。
DOI：
10.1039/b417942k
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
P. Botschwina
中科院分区：
文献类型：
--
作者：
C. Krekeler;M. Mladenović;P. Botschwina
利用耦合簇变量CCSD（T）和aug-cc-pVQZ基组，计算了有机阴离子HCO_2 ~-的六维势能面.由此，借助于离散变量表示，在称为DVR（6）的方法中获得了各种振动项能量和波函数。在15 cm ~（-1）范围内，计算的HCO ~（2-）和DCO ~（2-）的基本波数与最近氖基体隔离红外光谱的实验值一致。面外弯曲振动v4预测在1030和894 cm（-1）处。计算了DCO_2 ~-振动态v_1和2v_4之间的中等强度费米共振相互作用。13 C和18 O同位素位移与实验结果非常吻合（误差小于0.7cm（-1））。对甲酸根离子的八种同位素异构体的基态转动常数进行了精确的预测，并对离解过程HCO_2- -> H ~- + CO_2进行了较为详细的研究，预测离解能D_0为216 kJ·mol ~（-1）。
Making use of the coupled cluster variant CCSD(T) and the aug-cc-pVQZ basis set a six-dimensional (6D) potential energy surface has been calculated for HCO2-, a fundamental organic anion. Therefrom, a variety of vibrational term energies and wavefunctions has been obtained by means of the discrete variable representation in an approach termed DVR(6). Calculated wavenumbers of the fundamentals of HCO2- and DCO2- agree with recent experimental values from neon matrix isolation IR spectroscopy within 15 cm(-1). The out-of-plane bending vibrations v4 are predicted at 1030 and 894 cm(-1). Moderately strong Fermi resonance interaction is calculated between vibrational states v1 and 2v4 of DCO2-. Excellent agreement with experiment (differences less than 0.7 cm(-1) is observed for the 13C and 18O isotopic shifts. Accurate ground-state rotational constants are predicted for eight different isotopomers of the formate ion and the dissociation process HCO2- --> H- + CO2 is investigated in some detail, with the dissociation energy D0 predicted to be 216 kJ mol(-1).