Infrared spectroscopy of carbo-ions. III. ν3 band of methyl cation CH+3

Abstract

A study of the structure and dynamics of the hydronium ion by high resolution infrared laser spectroscopy. III. The ν3 band of D3O+ J. Chem. Phys. 92, 3257 (1990); 10.1063/1.457884 Infrared spectroscopy of carboions. V. Classical vs nonclassical structure of protonated acetylene C2H+ 3 J. Chem. Phys. 91, 5139 (1989); 10.1063/1.457612 Infrared spectroscopy of carboions. IV. The A 2Π u -X 2Σ+ g electronic transition of C− 2 J. Chem. Phys. 89, 129 (1988); 10.1063/1.455731Infrared spectra of carboions. II. ν3 band of acetylene ion C2H+ 2(2Π u )

Theoretical Calculations of Infrared Bands of CH3+and CH5+

“…In Figure 2, we show three optimized (CCSD(T)/cc-pVTZ) structures of CH 5 + with symmetries C s (I), C s (II), and C 2v . The C s (I) structure is the energy minimum structure, and the other two structures correspond to saddle points.…”

“…[7][8][9] The information on the quantum mechanical property of CH 3 + was obtained from the previous spectroscopic studies. 5,[10][11][12] Theoretical calculations 13,14 have also reported that the two vibrational states of CH 3 + lie quite close to each other. The determination of vibrational frequencies by computational methods has become increasingly important in many areas in chemistry.…”

“…Protonated methyl cation (CH 5 + ) is one of the important reactive species in combustion, atmospheric, and interstellar chemistry. High-resolution infrared spectrum of CH 5 + corresponding to the C-H stretching band in the 3.4 μm region was reported.…”

“…But it has other two low energy structures C s (II) and C 2v symmetric structure with almost no barrier. Recent theoretical investigations of CH 5 + have been performed to understand the dynamics and infrared spectrum of CH 5 + .…”

“…By using Gaussian 09 package, 16 we have optimized the geometries and calculated vibrational frequencies of CH 3 + and CH 5 + by using ab initio quantum mechanical methods and density functional theory (DFT) methods. Harmonic vibrational frequencies were determined by the analytical evaluation of the second derivative of the energy with respect to nuclear displacement.…”