First high-resolution analysis of the fundamental bands of (SiD4)-Si-29 and (SiD4)-Si-30: Line positions and strengths

摘要

The high resolution infrared spectra of (SiD4)-Si-M (M = 29,30) in natural abundance of Si-M (92.23% of Si-28, 4.68% of Si-29, and 3.09% of Si-30) were measured with Bruker IFS120 and IFS125 HR Fourier transform infrared spectrometers at an optical resolution between 0.00096 and 0.0025 cm(-1) and analyzed in the regions of 550-800 cm(-1) and 1480-1700 cm(-1) where the four fundamental bands, v(2), v(4), v(1) and v(3) are located. The 840/1641/888 transitions with J(max) = 31/31135 and 638/1356/838 transitions with J(max) = 31/31/34 were assigned to the 03, 04, and v3 bands of (SiD4)-Si-29 and (SiD4)-Si-30. The subsequent weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes the resonance interactions between pairs of vibrational states (0010, F-2)/(1000, A(1)) and (0001, F-2)/(0100, E) into account. As a result, sets of 22 and 22 fitted parameters were obtained which reproduces the initial 3369 and 2832 ro-vibrational transitions of the (SiD4)-Si-29 and (SiD4)-Si-30 isotopologues with the d(rms) = 2.34 x 10(-4) cm(-1) and 2.67 x 10(-4) cm(-1), respectively. An analysis of 221 and 134 experimental ro-vibrational lines of the v(4)/v(2) and v(3) bands of (SiD4)-Si-29 and (SiD4)-Si-30 was performed using the Hartmann-Tran profile to simulate the measured line shape and to determine experimental line intensities. A detailed line list of transitions of (SiD4)-Si-29 and (SiD4)-Si-30 in the studied regions is generated. (C) 2018 Elsevier Ltd. All rights reserved.